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Icaronycteris gunnelli sp. nov. Holotype AMNH: FM: 145747A,B (part and counterpart), an articulated skeleton including skull and mandibles with restoration (Figs 1 and 2). Paratype ROM:Palaeobiology-Vertebrate Fossils: 52666, an articulated skeleton including skull and mandibles (Fig 3). Locality, horizon, and age The holotype was found by Terry Rickords on August 16, 2017 at the American Fossil Quarry (previously known as the Thompson Ranch South Quarry or (South) Dempsey Quarry), Lincoln County, Wyoming (N41˚51.872’ W 110˚40.491’), ± 1, 15 meter below the Tri-ash layer in the sandwich beds of the Fossil Butte Member (FBM) (Figs 4 and 5), Green River Formation (GRF), late early Eocene (Lostcabinian, Wasatchian Biochron Wa-7). This locality preserves near-shore lacustrine deposits of Fossil Lake [40, 50]. The volcanic ash layer near the top of the FBM is radiometrically dated at 51.98 ± 0.34 Ma [51, 52]. Deposition rates are unknown in Fossil Lake. Deposition near-shore is more rapid than mid-lake [53], confounding efforts to estimate rates of deposition. Until reliable deposition rates are established there is no reliable means to estimate ages of specimens. The paratype was found in the same quarry as the holotype by Robert Kronner in 1994 in the bottom 60 cm of the sandwich beds of the FBM, Green River Formation. Etymology This species name is in honor of Gregg Gunnell in recognition of his extensive contributions to the understanding of fossil bats and chiropteran evolution. Diagnosis Icaronycteris gunnelli is the smallest known chiropteran from the Green River Formation (S 1 Table) and is distinguished from other Eocene bats by the following combination of traits: claw present on wing digit I and II; tiny ossified third phalanx present on wing digit III–V; relatively short forearm and broad wing; relatively short, robust hind limbs with a possibly sutured tibia and fibula; lower canine tall and lanceolate; upper canine with anteromedial groove; diastema present between C and P1; P3 with raised lingual cingulum and a crown length relatively shorter than that of P4; P4 with well-developed lingual cingular cusp and labial cingulum; P4 length and width subequal; upper molars with strongly developed ectocingulum. Description and comparisons The skull of the holotype of Icaronycteris gunnelli is dorsoventrally crushed, so many cranial features, including structures of the basicranium, cannot be distinguished. However, the shape of the skull and several important traits of the skull and postcranium can be evaluated. Morphological traits of I. gunnellii are similar to those seen in Icaronycteris index and Onychonycteris finneyi except if explicitly stated otherwise below. The proclivous premaxilla in Icaronycteris gunnelli extends anteriorly beyond the level of the canine root and the nasal process of the premaxilla is well developed. The zygomatic arch appears complete and is broader than the mastoid region. Parietals appear to have not been inflated based on their rounded shape. The angular process of the dentary in I. gunnelli projects below the level of the occlusal plane, and the coronoid process is approximately two times the height of the condylar process. The dental formula of I. gunnelli is I2 /3, C1/1, P3/3, M3/3 = 38. The upper incisors are orthodont and orthoclivous, and in this they resemble those of Onychonycteris finneyi. In contrast, the upper incisors in I. index are proodont and orthoclivous. The crowns of the upper incisors are not clearly differentiated from the root shafts in I. gunnelli, a condition similar to I. index but different from that seen in O. finneyi, in which the crown and root shaft of the upper incisors are clearly differentiated. The occlusal margin of I1 includes a large main cusp that is offset mesially from the axis of the tooth and tapers to a blunt point. A distal accessory cusp is present lateral to the main cusp on I1, with the accessory cusp approximately ¼ the size of the main cusp. The two upper incisors are subequal in height. Crown morphology of I2 is well developed and lingual cingulum is absent. Lack of lingual cingulum of the I2 is a characteristic also seen in I. index, whereas a lingual cingulum is present on this tooth in O. finneyi. I1 and I2 are subequal in height in I. gunnelli, also a condition shared with I. index. In contrast, in O. finneyi the height of I1 is less than that of I2. The upper canine (C) is separated from I2 by a diastema in all of these taxa. The upper canine in I. gunnelli is elongated anteroposteriorly but does not project anteriorly. This tooth is not labially swollen and it lacks a raised cingulum or accessory cusp. No lingual cingulum is present, which is another trait shared with I. index. By contrast, O. finneyi exhibits a faint lingual cingulum on the upper C. The distal cingulum of the upper canine is small in I. gunnelli. A labial cingulum on the canine was not visible on the X-ray, but we could not determine if this indicated true absence or a lack of resolution in our images. An anteromedial groove is present on the upper canine, a structure that is not present in I. index or O. finneyi. A posteromedial ridge is present and the posterolingual and posterolabial surfaces of the canine are flattened. The upper canine has a tiny posterolateral accessory cusp, a structure that is absent in O. finneyi, and present but slightly smaller in I. index. The shape of this cusp is conical and is not clearly separated from the main cusp; it originates on the posterior face of the main cusp. A diastema is present between upper C and P1. The upper premolars lie in line with the molar toothrow and no teeth are offset medially or laterally. The P1 is single rooted. This tooth has a well-developed crown which lacks a labial cingulum, similar to I. index but differing from O. finneyi, which has a labial cingulum on P1. The P 3 in I. gunnelli also lacks a labial cingulum, again as in I. index, with both Icaronycteris species differing from O. finneyi, which exhibits a weakly developed labial cingulum on P3. The lingual cingulum of P3 is weakly developed and lacks a cusp, but the edge of the cingulum is slightly raised. This differs from the condition in I. index and O. finneyi, both of which have a lingual cusp on P3. The crown length of P1 is shorter than that of P3. This condition is shared with I. index, while P1 and P3 are subequal in crown length in O. finneyi. The postparacrista of P3 extends as a single crest to the distal edge of the tooth and lacks a distal accessory cusp. Both P3 and P4 have three roots, but the crown length of P3 is shorter than that of P4. The latter trait contrasts with the condition in I. index and O. finneyi, both of which have a P3 that is longer than P4. The height of P3 is subequal to that of P 4 in I. gunnelli. This differs from both I. index, which has a P3 that is taller than P4, and from O. finneyi, in which P3 is shorter in height than the P4. No diastema present between the P3 and P4. The lingual cingulum of the P4 is very large and resembles that of I. index. In both of these taxa, the lingual cingulum forms a distinct lobe that extends posteriorly as far as the protocone of the first molar. This condition differs from that seen in O. finneyi, where the lobe of the lingual cingulum does not extend as far as the protocone of the first molar. The labial cingulum of the P4 is well developed in I. gunnelli and O. finneyi, but absent in I. index. The P 4 in I. gunnelli has three roots. The lingual cingulum of the P4 is very large and resembles that of I. index. In both of these taxa, the lingual cingulum forms a distinct lobe that extends posteriorly as far as the protocone of the first molar. This condition differs from that seen in O. finneyi, where the lobe of the lingual cingulum does not extend as far as the protocone of the first molar. The labial cingulum of the P4 is well developed in I. gunnelli and O. finneyi, but absent in I. index. A lingual cingular cusp is well developed on P 4 in I. gunnelli. This differs from the condition in I. index, in which the lingual cingular cusp is weakly developed. The condition of a lingual cingular cusp in O. finneyi cannot be determined from the specimens available. The P4 postparacrista is a single crest that extends as a continuous crest to the distal aspect of the tooth. The length and width of the P4 are subequal in I. gunnelli, in contrast to the conditions seen in I. index (P4 wider than long) and O. finneyi (P4 longer than wide). The upper molars of I. gunnelli are characterized by a strongly developed ectocingulum. This is similar to the condition seen in O. finneyi, but differs from that in I. index, in which the ectocingulum is present but weak. A lingual cingulum and stylar shelf are present on both the M1 and M2, and the protocone and paracone are subequal in height. The protocone on both M1 and M2 is sharp and inclined anteriorly. The angle between the postparacrista and premetacrista is acute. The postparacrista contacts the premetacrista on the labial aspect of the tooth and closes the trigon basin labially on both M1 and M2. The trigon basin on both teeth is wide and shallow, and a mesostyle and mesostylar crest are absent. The contact between the postparacrista and premetacrista is more lingually displaced than the condition observed in I. index and similar to that of O. finneyi, and both M1 and M2 have a cuspule on the premetacrista as well as a small paraconule. The maximum mesiodistal length of M1 and M2 is less than half the distance between the paracone and metacone of the respective teeth. The M1 has a long, straight, crestlike, parastyle that is not separated from the preparacrista. A single deep ectoflexus is present labial to the mesostyle. The preparacrista of M1 is subequal in length to the postparacrista, and the postmetacrista is about 1.5 times longer than the premetacrista. The trigon basin does not show any striations or enamel folds, instead being relatively smooth. The postprotocrista is oriented distolabially towards the metacone, and it extends labially to become confluent with the metacingulum and the edge of the hypocone shelf. A metaconule is present on the M1, but an endoloph is absent. The hypocone shelf is small and narrow but clearly distinct from the trigon basin. The M2 parastyle is crestlike and curved. Like M1, the M2 has a single deep exoflexus labial to the mesostyle. The metacone is located directly posterior to the paracone. The M2 postmetacrista, which is oriented distolabially towards the metacone, is 1.75 times longer than the premetacrista. An endoloph is present on M1, but is lacking on M2. The hypocone shelf on the M2 is very small and appears only as a narrow cingulum; no hypocone cusp is present. The M3 is moderately reduced with a surface area The three lower incisors in I. gunnelli are trilobed and somewhat procumbent; they are all similar in size and shape. The alveoli are evenly spaced, and there is no diastema between the last incisor and lower canine. The lower canine is tall, lanceolate, and lacks an anterior cuspule. The posterior cingulid on the canine is broad and a posterobasal cusp is strongly developed. The labial cingulum and cingular structures of the canine are not clearly visible given preservation of the holotype of I. gunnelli and hence cannot be evaluated. As in other Eocene bats, I. gunnelli has three lower premolars. The p1 is large, single-rooted, cuspidate and has a distal cuspule. The crown length of p1 is less than that of p3. This is similar to the condition seen in I. index, but different from that of O. finneyi, in which p1 crown length is greater than p3 length. The p3 is premolariform, i.e., the cusps are not arranged in a tribosphenic pattern. Anterolingual and distal cuspules are present, but there is no lingual cuspule. Both p3 and p4 have two roots that are oriented longitudinally with respect to the long axis of the tooth row. The crowns of p3 and p4 are subequal in height and length but differ in morphology; in contrast to p3, the p4 is tribosphenic with a distinct trigonid and talonid. The paraconid of p4 consists of a single large cusp supporting a paracristid; this tooth also has a large metaconid, a long protocristid, and a long talonid. The protoconid is tall, sharp and slender. Labial structures on the premolars are not visible and therefore cannot be described in detail. The lower molars of I. gunnelli lack a lingual cingulid and the trigonid fovea is open lingually. The hypoconulid is located on the distolingual border of the talonid, well separated from the entoconid and closer to the midline than to the entoconid. The height of the lingual cusps appears relatively low compared to the labial cusps. The entocristid is disrupted (the entocristid is short so that talonid basin drains lingually) on all three lower molars. The m1 and m2 are subequal in size and have similar crown morphology including a well-developed protoconid, paraconid, and metaconid. I. gunnelli and I. index both have a large hypoconulid on the m1 and m2, but in O. finneyi the hypoconulids on these teeth are small and low. The protoconid on m1 is markedly higher than the hypoconid, but is subequal in height to the protoconids on the m2 and m3. The m3 has two roots and bears a large hypoconulid. The axial skeleton of I. gunnelli generally resembles that of other Eocene bats. An accurate vertebral count in the thoracolumbar region could not be determined due to poor preservation. The tail has 11 free caudal vertebrae. The scapula has an acromion process that extends anterolaterally beyond the glenoid fossa, and the lateral and dorsal edges of the acromion are flat. The infraspinous fossa is narrow and triangular shaped, tapering anteriorly towards the glenoid. A thick lip is present along the axillary border of the scapula. The coracoid process is short, stout, and appears to curve ventrolaterally. Like other known Eocene bats, I. gunnelli has a well-developed wing skeleton with elongated hand and finger bones. The relative length of the humerus compared to the radius is ~76%, which is comparable to that of O. finneyi (~76%) while somewhat greater than that of I. index (~71%). The head of the humerus is spherical, and the distal articular surface of the humerus is laterally displaced. The distal end of the radius is wider than the mean width of the shaft. An ossified ulnar patella is present. The ulna and radius are fused distally starting at approximately the midpoint of the forearm. The metacarpal formula is IV ≥ V = III> II> I. The hindlimb of I. gunnelli slightly differs from other Green River bats. The greater trochanter does not extend proximally as far as the femoral head, which differs from the condition seen in I. index and O. finneyi, in which the greater trochanter extends as far proximally as the level of the femoral head. The lesser trochanter is large and forms an extended flange in I. gunnelli as in O. finneyi. By contrast, the lesser trochanter is present only as a small tubercle in I. index. A third trochanter is absent in all three Green River bat taxa. The femur shaft is straight in anterior view and a femoral neck is absent. A small articulation is present between the distal ends of the tibia and fibula. The fibula is fully ossified and the proximal ends of the fibula and tibia are possibly sutured. The first digit of the foot is shorter than the remaining digits. There is no visible contact between metatarsals of adjacent digits although intermetatarsal contact and/or facets may have been present, but are not detectable in our specimens. The shape of the proximal margin of the proximal phalanx seems to be flat in lateral view, but it is possible that this is due to taphonomic alteration. Foot digits II–V each have three phalanges. Phylogenetic relationships Phylogenetic analyses including all taxa resulted in three most parsimonious trees (MPTs) of 1511 steps (Fig 6A). The strict consensus tree recovered a sister relationship between Icaronycteris gunnelli and Icaronycteris index with high bootstrap support (bootstrap value 100). Onychonycteris finneyi fell sister to the Icaronycteris clade with lower support (bootstrap value 52), while Archaeonycteris trigonodon was recovered sister to the clade of Green River bats with low support (bootstrap value 37). Icaronycteris menui fell sister to the above clade in the strict consensus tree, also with low bootstap support (bootstrap value 46). The only other clade recovered in the strict consensus tree is the sister relationship between Rhinolophus ferrumequinum and Rhinopoma hardwickii, which received relatively high support (bootstrap value 76). Tachypteron franzeni in this analysis occurred in a polytomy with the previously mentioned clades, the remaining extant bats, Palaeochiropteryx tupaiodon, Hassianycteris messelensis, Icaronycteris ? menui, and I. sigei. Due to the fragmentary nature of both Icaronycteris menui and I. sigei, we conducted a second analysis omitting those taxa. This analysis resulted in two MPTs of 1420 steps each (Fig 6B). The strict consensus tree again recovers an I. gunnelli and I. index sister relationship, with O. finneyi basal to that clade. Archaeonycteris trigonodon falls in a polytomy to the Green River bats in this analysis, along with a clade consisting of Palaeochiropteryx tupaiodon and Hassianycteris messelensis. The I. gunnelli + I. index clade again received high bootstrap support (bootstrap value 100), while the position of O. finneyi basal to that clade also received high support (bootstrap value 89). The position of A. trigonodon basal to the Green River clade received lower support (bootstrap value 54), as did the polytomy of the Green River bats + Archaeonycteris plus P. tupaiodon and H. messelensis (bootstrap value 56). Tachypteron franzeni in this analysis fell sister to a clade consisting of the exta

Icaronycteris gunnelli sp. nov. Holotype AMNH: FM: 145747A,B (part and counterpart), an articulated skeleton including skull and mandibles with restoration (Figs 1 and 2). Paratype ROM:Palaeobiology-Vertebrate Fossils: 52666, an articulated skeleton including skull and mandibles (Fig 3). Locality, horizon, and age The holotype was found by Terry Rickords on August 16, 2017 at the American Fossil Quarry (previously known as the Thompson Ranch South Quarry or (South) Dempsey Quarry), Lincoln County, Wyoming (N41˚51.872’ W 110˚40.491’), ± 1, 15 meter below the Tri-ash layer in the sandwich beds of the Fossil Butte Member (FBM) (Figs 4 and 5), Green River Formation (GRF), late early Eocene (Lostcabinian, Wasatchian Biochron Wa-7). This locality preserves near-shore lacustrine deposits of Fossil Lake [40, 50]. The volcanic ash layer near the top of the FBM is radiometrically dated at 51.98 ± 0.34 Ma [51, 52]. Deposition rates are unknown in Fossil Lake. Deposition near-shore is more rapid than mid-lake [53], confounding efforts to estimate rates of deposition. Until reliable deposition rates are established there is no reliable means to estimate ages of specimens. The paratype was found in the same quarry as the holotype by Robert Kronner in 1994 in the bottom 60 cm of the sandwich beds of the FBM, Green River Formation. Etymology This species name is in honor of Gregg Gunnell in recognition of his extensive contributions to the understanding of fossil bats and chiropteran evolution. Diagnosis Icaronycteris gunnelli is the smallest known chiropteran from the Green River Formation (S 1 Table) and is distinguished from other Eocene bats by the following combination of traits: claw present on wing digit I and II; tiny ossified third phalanx present on wing digit III–V; relatively short forearm and broad wing; relatively short, robust hind limbs with a possibly sutured tibia and fibula; lower canine tall and lanceolate; upper canine with anteromedial groove; diastema present between C and P1; P3 with raised lingual cingulum and a crown length relatively shorter than that of P4; P4 with well-developed lingual cingular cusp and labial cingulum; P4 length and width subequal; upper molars with strongly developed ectocingulum. Description and comparisons The skull of the holotype of Icaronycteris gunnelli is dorsoventrally crushed, so many cranial features, including structures of the basicranium, cannot be distinguished. However, the shape of the skull and several important traits of the skull and postcranium can be evaluated. Morphological traits of I. gunnellii are similar to those seen in Icaronycteris index and Onychonycteris finneyi except if explicitly stated otherwise below. The proclivous premaxilla in Icaronycteris gunnelli extends anteriorly beyond the level of the canine root and the nasal process of the premaxilla is well developed. The zygomatic arch appears complete and is broader than the mastoid region. Parietals appear to have not been inflated based on their rounded shape. The angular process of the dentary in I. gunnelli projects below the level of the occlusal plane, and the coronoid process is approximately two times the height of the condylar process. The dental formula of I. gunnelli is I2 /3, C1/1, P3/3, M3/3 = 38. The upper incisors are orthodont and orthoclivous, and in this they resemble those of Onychonycteris finneyi. In contrast, the upper incisors in I. index are proodont and orthoclivous. The crowns of the upper incisors are not clearly differentiated from the root shafts in I. gunnelli, a condition similar to I. index but different from that seen in O. finneyi, in which the crown and root shaft of the upper incisors are clearly differentiated. The occlusal margin of I1 includes a large main cusp that is offset mesially from the axis of the tooth and tapers to a blunt point. A distal accessory cusp is present lateral to the main cusp on I1, with the accessory cusp approximately ¼ the size of the main cusp. The two upper incisors are subequal in height. Crown morphology of I2 is well developed and lingual cingulum is absent. Lack of lingual cingulum of the I2 is a characteristic also seen in I. index, whereas a lingual cingulum is present on this tooth in O. finneyi. I1 and I2 are subequal in height in I. gunnelli, also a condition shared with I. index. In contrast, in O. finneyi the height of I1 is less than that of I2. The upper canine (C) is separated from I2 by a diastema in all of these taxa. The upper canine in I. gunnelli is elongated anteroposteriorly but does not project anteriorly. This tooth is not labially swollen and it lacks a raised cingulum or accessory cusp. No lingual cingulum is present, which is another trait shared with I. index. By contrast, O. finneyi exhibits a faint lingual cingulum on the upper C. The distal cingulum of the upper canine is small in I. gunnelli. A labial cingulum on the canine was not visible on the X-ray, but we could not determine if this indicated true absence or a lack of resolution in our images. An anteromedial groove is present on the upper canine, a structure that is not present in I. index or O. finneyi. A posteromedial ridge is present and the posterolingual and posterolabial surfaces of the canine are flattened. The upper canine has a tiny posterolateral accessory cusp, a structure that is absent in O. finneyi, and present but slightly smaller in I. index. The shape of this cusp is conical and is not clearly separated from the main cusp; it originates on the posterior face of the main cusp. A diastema is present between upper C and P1. The upper premolars lie in line with the molar toothrow and no teeth are offset medially or laterally. The P1 is single rooted. This tooth has a well-developed crown which lacks a labial cingulum, similar to I. index but differing from O. finneyi, which has a labial cingulum on P1. The P 3 in I. gunnelli also lacks a labial cingulum, again as in I. index, with both Icaronycteris species differing from O. finneyi, which exhibits a weakly developed labial cingulum on P3. The lingual cingulum of P3 is weakly developed and lacks a cusp, but the edge of the cingulum is slightly raised. This differs from the condition in I. index and O. finneyi, both of which have a lingual cusp on P3. The crown length of P1 is shorter than that of P3. This condition is shared with I. index, while P1 and P3 are subequal in crown length in O. finneyi. The postparacrista of P3 extends as a single crest to the distal edge of the tooth and lacks a distal accessory cusp. Both P3 and P4 have three roots, but the crown length of P3 is shorter than that of P4. The latter trait contrasts with the condition in I. index and O. finneyi, both of which have a P3 that is longer than P4. The height of P3 is subequal to that of P 4 in I. gunnelli. This differs from both I. index, which has a P3 that is taller than P4, and from O. finneyi, in which P3 is shorter in height than the P4. No diastema present between the P3 and P4. The lingual cingulum of the P4 is very large and resembles that of I. index. In both of these taxa, the lingual cingulum forms a distinct lobe that extends posteriorly as far as the protocone of the first molar. This condition differs from that seen in O. finneyi, where the lobe of the lingual cingulum does not extend as far as the protocone of the first molar. The labial cingulum of the P4 is well developed in I. gunnelli and O. finneyi, but absent in I. index. The P 4 in I. gunnelli has three roots. The lingual cingulum of the P4 is very large and resembles that of I. index. In both of these taxa, the lingual cingulum forms a distinct lobe that extends posteriorly as far as the protocone of the first molar. This condition differs from that seen in O. finneyi, where the lobe of the lingual cingulum does not extend as far as the protocone of the first molar. The labial cingulum of the P4 is well developed in I. gunnelli and O. finneyi, but absent in I. index. A lingual cingular cusp is well developed on P 4 in I. gunnelli. This differs from the condition in I. index, in which the lingual cingular cusp is weakly developed. The condition of a lingual cingular cusp in O. finneyi cannot be determined from the specimens available. The P4 postparacrista is a single crest that extends as a continuous crest to the distal aspect of the tooth. The length and width of the P4 are subequal in I. gunnelli, in contrast to the conditions seen in I. index (P4 wider than long) and O. finneyi (P4 longer than wide). The upper molars of I. gunnelli are characterized by a strongly developed ectocingulum. This is similar to the condition seen in O. finneyi, but differs from that in I. index, in which the ectocingulum is present but weak. A lingual cingulum and stylar shelf are present on both the M1 and M2, and the protocone and paracone are subequal in height. The protocone on both M1 and M2 is sharp and inclined anteriorly. The angle between the postparacrista and premetacrista is acute. The postparacrista contacts the premetacrista on the labial aspect of the tooth and closes the trigon basin labially on both M1 and M2. The trigon basin on both teeth is wide and shallow, and a mesostyle and mesostylar crest are absent. The contact between the postparacrista and premetacrista is more lingually displaced than the condition observed in I. index and similar to that of O. finneyi, and both M1 and M2 have a cuspule on the premetacrista as well as a small paraconule. The maximum mesiodistal length of M1 and M2 is less than half the distance between the paracone and metacone of the respective teeth. The M1 has a long, straight, crestlike, parastyle that is not separated from the preparacrista. A single deep ectoflexus is present labial to the mesostyle. The preparacrista of M1 is subequal in length to the postparacrista, and the postmetacrista is about 1.5 times longer than the premetacrista. The trigon basin does not show any striations or enamel folds, instead being relatively smooth. The postprotocrista is oriented distolabially towards the metacone, and it extends labially to become confluent with the metacingulum and the edge of the hypocone shelf. A metaconule is present on the M1, but an endoloph is absent. The hypocone shelf is small and narrow but clearly distinct from the trigon basin. The M2 parastyle is crestlike and curved. Like M1, the M2 has a single deep exoflexus labial to the mesostyle. The metacone is located directly posterior to the paracone. The M2 postmetacrista, which is oriented distolabially towards the metacone, is 1.75 times longer than the premetacrista. An endoloph is present on M1, but is lacking on M2. The hypocone shelf on the M2 is very small and appears only as a narrow cingulum; no hypocone cusp is present. The M3 is moderately reduced with a surface area I. gunnelli are trilobed and somewhat procumbent; they are all similar in size and shape. The alveoli are evenly spaced, and there is no diastema between the last incisor and lower canine. The lower canine is tall, lanceolate, and lacks an anterior cuspule. The posterior cingulid on the canine is broad and a posterobasal cusp is strongly developed. The labial cingulum and cingular structures of the canine are not clearly visible given preservation of the holotype of I. gunnelli and hence cannot be evaluated. As in other Eocene bats, I. gunnelli has three lower premolars. The p1 is large, single-rooted, cuspidate and has a distal cuspule. The crown length of p1 is less than that of p3. This is similar to the condition seen in I. index, but different from that of O. finneyi, in which p1 crown length is greater than p3 length. The p3 is premolariform, i.e., the cusps are not arranged in a tribosphenic pattern. Anterolingual and distal cuspules are present, but there is no lingual cuspule. Both p3 and p4 have two roots that are oriented longitudinally with respect to the long axis of the tooth row. The crowns of p3 and p4 are subequal in height and length but differ in morphology; in contrast to p3, the p4 is tribosphenic with a distinct trigonid and talonid. The paraconid of p4 consists of a single large cusp supporting a paracristid; this tooth also has a large metaconid, a long protocristid, and a long talonid. The protoconid is tall, sharp and slender. Labial structures on the premolars are not visible and therefore cannot be described in detail. The lower molars of I. gunnelli lack a lingual cingulid and the trigonid fovea is open lingually. The hypoconulid is located on the distolingual border of the talonid, well separated from the entoconid and closer to the midline than to the entoconid. The height of the lingual cusps appears relatively low compared to the labial cusps. The entocristid is disrupted (the entocristid is short so that talonid basin drains lingually) on all three lower molars. The m1 and m2 are subequal in size and have similar crown morphology including a well-developed protoconid, paraconid, and metaconid. I. gunnelli and I. index both have a large hypoconulid on the m1 and m2, but in O. finneyi the hypoconulids on these teeth are small and low. The protoconid on m1 is markedly higher than the hypoconid, but is subequal in height to the protoconids on the m2 and m3. The m3 has two roots and bears a large hypoconulid. The axial skeleton of I. gunnelli generally resembles that of other Eocene bats. An accurate vertebral count in the thoracolumbar region could not be determined due to poor preservation. The tail has 11 free caudal vertebrae. The scapula has an acromion process that extends anterolaterally beyond the glenoid fossa, and the lateral and dorsal edges of the acromion are flat. The infraspinous fossa is narrow and triangular shaped, tapering anteriorly towards the glenoid. A thick lip is present along the axillary border of the scapula. The coracoid process is short, stout, and appears to curve ventrolaterally. Like other known Eocene bats, I. gunnelli has a well-developed wing skeleton with elongated hand and finger bones. The relative length of the humerus compared to the radius is ~76%, which is comparable to that of O. finneyi (~76%) while somewhat greater than that of I. index (~71%). The head of the humerus is spherical, and the distal articular surface of the humerus is laterally displaced. The distal end of the radius is wider than the mean width of the shaft. An ossified ulnar patella is present. The ulna and radius are fused distally starting at approximately the midpoint of the forearm. The metacarpal formula is IV ≥ V = III> II> I. The hindlimb of I. gunnelli slightly differs from other Green River bats. The greater trochanter does not extend proximally as far as the femoral head, which differs from the condition seen in I. index and O. finneyi, in which the greater trochanter extends as far proximally as the level of the femoral head. The lesser trochanter is large and forms an extended flange in I. gunnelli as in O. finneyi. By contrast, the lesser trochanter is present only as a small tubercle in I. index. A third trochanter is absent in all three Green River bat taxa. The femur shaft is straight in anterior view and a femoral neck is absent. A small articulation is present between the distal ends of the tibia and fibula. The fibula is fully ossified and the proximal ends of the fibula and tibia are possibly sutured. The first digit of the foot is shorter than the remaining digits. There is no visible contact between metatarsals of adjacent digits although intermetatarsal contact and/or facets may have been present, but are not detectable in our specimens. The shape of the proximal margin of the proximal phalanx seems to be flat in lateral view, but it is possible that this is due to taphonomic alteration. Foot digits II–V each have three phalanges. Phylogenetic relationships Phylogenetic analyses including all taxa resulted in three most parsimonious trees (MPTs) of 1511 steps (Fig 6A). The strict consensus tree recovered a sister relationship between Icaronycteris gunnelli and Icaronycteris index with high bootstrap support (bootstrap value 100). Onychonycteris finneyi fell sister to the Icaronycteris clade with lower support (bootstrap value 52), while Archaeonycteris trigonodon was recovered sister to the clade of Green River bats with low support (bootstrap value 37). Icaronycteris menui fell sister to the above clade in the strict consensus tree, also with low bootstap support (bootstrap value 46). The only other clade recovered in the strict consensus tree is the sister relationship between Rhinolophus ferrumequinum and Rhinopoma hardwickii, which received relatively high support (bootstrap value 76). Tachypteron franzeni in this analysis occurred in a polytomy with the previously mentioned clades, the remaining extant bats, Palaeochiropteryx tupaiodon, Hassianycteris messelensis, Icaronycteris ? menui, and I. sigei. Due to the fragmentary nature of both Icaronycteris menui and I. sigei, we conducted a second analysis omitting those taxa. This analysis resulted in two MPTs of 1420 steps each (Fig 6B). The strict consensus tree again recovers an I. gunnelli and I. index sister relationship, with O. finneyi basal to that clade. Archaeonycteris trigonodon falls in a polytomy to the Green River bats in this analysis, along with a clade consisting of Palaeochiropteryx tupaiodon and Hassianycteris messelensis. The I. gunnelli + I. index clade again received high bootstrap support (bootstrap value 100), while the position of O. finneyi basal to that clade also received high support (bootstrap value 89). The position of A. trigonodon basal to the Green River clade received lower support (bootstrap value 54), as did the polytomy of the Green River bats + Archaeonycteris plus P. tupaiodon and H. messelensis (bootstrap value 56). Tachypteron franzeni in this analysis fell sister to a clade consisting of the exta, Published as part of Rietbergen, Tim B, van den Hoek Ostende, Lars W, Aase, Arvid, Jones, Matthew F, Medeiros, Edward D & Simmons, Nancy B, 2023, The oldest known bat skeletons and their implications for Eocene chiropteran diversification, pp. 1-20 in PloS one 18 (4) on pages 3-12, DOI: 10.1371/journal.pone.0283505, http://zenodo.org/record/7838220, {"references":["40. Buchheim HP, Cushman RA, Biaggi RE. Stratigraphic revision of the Green River Formation in Fossil Basin, Wyoming. Rocky Mt Geol 2011; 46: 165 - 181. https: // doi. org / 10.2113 / gsrocky. 46.2.165","50. Buchheim HP. Paleoenvironments, lithofacies, and varves of the Fossil Butte Member of the Eocene Green River Formation, southwest Wyoming. Univ Wyoming Contr Geol 1994; 30 3 - 14. https: // doi. org / 10.2113 / gsrocky. 30.1.3","51. Smith ME, Carroll A. R., Singer B Synoptic reconstruction of a major ancient lake system: Eocene Green River Formation, western United States. Geol Soc Am Bull 2008; 120: 54 - 84. https: // doi. org / 10. 1130 / B 26073.1","52. Smith ME, Chamberlain KR, Singer BS, Carroll A. R. Eocene clocks agree: Coeval 40 Ar / 39 Ar, U-Pb, and astronomical ages from the Green River Formation. Geology 2010; 38: 527 - 530. https: // doi. org / 10. 1130 / G 30630.1","53. Outhwaite GL. Paleoenvironments and salinity gradients of Eocene Fossil Lake during the K-spar Tuff time, Green River Formation, southwestern Wyoming. M. Sc. Thesis, Loma Linda University. 2001."]}

Subfamily Micronycterinae Van den Bussche, 1992 Two genera (Micronycteris and Lampronycteris) and 12 species are currently recognized in the subfamily Micronycterinae (Williams and Genoways, 2008; Larsen et al., 2011; Siles et al., 2013; Baker et al., 2016; Cirranello et al., 2016; Simmons and Cirranello, 2020). Members of this subfamily are small to medium-sized bats (forearm 32–46 mm) that can be recognized by the following combination of traits: noseleaf simple, with spear equal to or longer than twice the height of horseshoe; labial border of horseshoe fused to upper lip, forming a thickened ridge; chin with two dermal pads with smoothly rounded lateral margins; calcar equal to or longer than foot; ventral fur unicolored; and outer upper incisor in contact with canine (Cirranello et al., 2016). We recorded all seven micronycterine species expected to occur in the Yavarí-Ucayali interfluve., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 55, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Eptesicus furinalis (d’Orbigny and Gervais, 1847) Figure 32 VOUCHER MATERIAL (TOTAL = 2): Jenaro Herrera (ROM 122089, 122178); see table 59 for measurements. UNVOUCHERED OBSERVATIONS: We captured six individuals of Eptesicus furinalis between 16 and 21 February 2019 on the Tahuayo expedition, five at El Chino Village and one at Frog Valley. This species was also identified using acoustic methods during the CEBIO bat course at Jenaro Herrera in 2012. IDENTIFICATION: Eptesicus furinalis can be distinguished from other Neotropical congeners by its medium size (forearm 36–43 mm, greatest length of skull> 15 mm), relatively short (Eptesicus furinalis have been provided by Davis (1966), Barquez et al. (1999), Lim et al. (2005), Davis and Gardner (2008), and Sánchez et al. (2019). Two subspecies are currently recognized: E. f. furinalis (northern Argentina, Paraguay, Bolivia, Brazil, and Uruguay) and E. f. gaumeri (Mexico southward throughout Central America to Amazonian Brazil and Bolivia) (Davis and Gardner, 2008). Based on geography, material from the Yavarí-Ucayali interfluve should correspond to E. f. gaumeri, but this species is highly variable across its distribution, and the last revision of the genus (Davis, 1966) did not include any Peruvian samples. Until larger samples and genetic data become available, we recommend against formally recognizing subspecies of E. furinalis. The two specimens from Jenaro Herrera conform to previous descriptions of Eptesicus furinalis, with measurements that fall within the range of size variation previously documented for the species. The material we examined in the field at El Chino Village conformed to previous descriptions of the species, with yellowish ventral fur and external measurements that were within the range of size variation previously documented for Eptesicus furinalis. REMARKS: Of the eight recorded captures of Eptesicus furinalis from our region, three were taken in ground-level mistnets, two were taken in elevated nets, and three were taken in harp traps. Two captures were in primary forest and six were in clearings., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on pages 131-132, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Artibeus (Dermanura) bogotensis (Andersen, 1906) VOUCHER MATERIAL (TOTAL = 1): Jenaro Herrera (MUSM 1320); see table 40 for measurements. UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Artibeus bogotensis was originally described (Andersen, 1906b) as a subspecies of A. cinereus. It was subsequently variously treated as a subspecies of A. cinereus (e.g., by Andersen, 1906b, 1908; Cabrera, 1958; Koopman, 1994) or A. glaucus (e.g., by Handley, 1987; Simmons, 2005; Marques-Aguiar, 2008a), until Lim et al. (2008) raised it to full species rank. Artibeus bogotensis can be distinguished from other species in the subgenus Dermanura by the following combination of characteristics: palebrown to grayish dorsal pelage; tricolored dorsal fur; distinct white facial stripes; margins of ear pale cream or whitish; entire forearm covered by long, dense fur; uropatagium dark brown and sparsely furred; rostrum short, slender, and elevated (tilted upward); posterior palatal border V-shaped, with nearly straight sides; impression of optic nerve in orbit well developed; angular process well developed but not reaching the level of the condyloid process; second upper premolar caniniform; M1 with narrow talon; and m3 absent (Handley, 1987; Lim et al., 2008; Calderón and Pacheco, 2012; Solari, 2019b). Descriptions and measurements of A. bogotensis have been provided by Andersen (1906b, 1908), Handley (1987), Lim et al. (2005), Lim et al. (2008), and Calderón and Pacheco (2012). No subspecies are currently recognized (Lim et al., 2008). Ascorra et al. (1993) identified the specimen from Jenaro Herrera as Artibeus gnomus, but Calderón and Pacheco (2012) subsequently reidentified it as A. bogotensis, an assessment with which we concur. This specimen is the only record of the species in Peru. REMARKS: No ecological information accompanies the single recorded capture of Artibeus bogotensis from our region., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 98, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Vampyrodes caraccioli (Thomas, 1889) Figure 29 VOUCHER MATERIAL (TOTAL = 1): Quebrada Lobo (MUSA 15124); see table 51 for measurements. UNVOUCHERED OBSERVATIONS: One individual of Vampyrodes caraccioli was captured at Tapiche during the Sierra del Divisor Rapid Biological Inventory (Jorge and Velazco, 2006), and we captured a single individual at El Chino Village on 18 February 2019 (fig. 29). IDENTIFICATION: Before the revision by Velazco and Simmons (2011), Vampyrodes caraccioli was the sole member of the genus and was thought to range from Mexico to eastern Brazil. Two subspecies (V. c. caraccioli and V. c. major) were traditionally recognized (Koopman, 1994; Gardner, 2008j). After morphological, morphometric, and molecular analyses, Velazco and Simmons (2011) concluded that the two subspecies represented distinct species, of which only V. caraccioli sensu stricto is known to occur in South America east of the Andes. Vampyrodes caraccioli can be distinguished from other cis-Andean stenodermatines by the following characteristics: prominent white dorsal stripe and conspicuous white facial stripes, bicolored dorsal fur, tricolored ventral fur, presence of a fringe of hairs on the edge of the uropatagium, lingual cingula absent at the bases of the metacones of the upper molars, lack of M3, the presence of two cuspules on the posterior cristid of the second upper premolar, and lingual cingulid absent on the first lower molar (Gardner, 2008j; Velazco and Simmons, 2011). Descriptions and measurements of V. caraccioli were provided by Husson (1954), Swanepoel and Genoways (1979), Lim et al. (2005), Velazco et al. (2010b), Velazco and Simmons (2011), Carvalho et al. (2014), Lopes et al. (2016), and Althoff et al. (2017). No subspecies are currently recognized (Velazco and Simmons, 2011). Medina et al. (2015) identified the specimen from Quebrada Lobo as Vampyrodes caraccioli based only on external characters because the skull had not been removed from the body. Nevertheless, the provenance of the specimen in addition to the presence of a few characteristics observable in fluid specimens (presence of a fringe of hairs on the edge of the uropatagium, lack of M3, and the presence of two cuspules on the posterior cristid of the second upper premolar) confirms the identity of the specimens as V. caraccioli., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on pages 121-122, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Noctilio leporinus (Linnaeus, 1758) VOUCHER MATERIAL (TOTAL = 15): Quebrada Esperanza (FMNH 89002–89012, 89161–89164); see table 14 for measurements. UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Noctilio leporinus is easily distinguished from N. albiventris by its larger size (wingspan about 500 mm; length of foot> 25 mm; forearm> 73 mm; length of maxillary toothrow> 10 mm), including especially long hindlimbs, large feet, and well-developed claws that it uses for gaffing fish (Hood and Jones, 1984; Gardner, 2008a; López-Baucells et al., 2018). Descriptions and measurements of N. leporinus were provided by Husson (1962, 1978), Ceballos-Bendezú (1968), Davis (1973), Hood and Jones (1984), and Simmons and Voss (1998). Although three subspecies have traditionally been recognized (e.g., by Davis, 1973; Simmons, 2005; Gardner, 2008a), recent molecular studies support the recognition of only two: N. l. leporinus (in South America east of the Andes extending north into eastern Panama) and N. l. mastivus (distributed from Mexico south into the lowlands west of the Andes, with an additional population in Jamaica) (Pavan et al., 2013; Khan et al., 2014). Ceballos-Bendezú (1968) correctly identified the specimens from Quebrada Esperanza as Noctilio leporinus. Our comparisons indicate that these specimens are morphologically indistinguishable from specimens from Bolivia (e.g., AMNH 210666), Brazil (e.g., AMNH 91943), and French Guiana (e.g., AMNH 265974). This result is congruent with the genetic findings of Pavan et al. (2013) and Khan et al. (2014) and suggests that the Quebrada Esperanza specimens should be referred to N. l. leporinus. REMARKS: No ecological information accompanies the unique series from Quebrada Esperanza, which was obtained by C. Kalinowski in 1957, but from the fact that these specimens were collected on three different dates (1 on 23 September, 10 on 25 September, and 4 on 26 September), we infer the probable occurrence of multiple capture events. Because mistnets were seldom employed in the 1950s, these bats were probably shot at night by jacklight or taken from diurnal roosts., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 30, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Vampyrum spectrum (Linnaeus, 1758) VOUCHER MATERIAL: None. UNVOUCHERED OBSERVATIONS: Ascorra et al. (1991) reported capturing an unspecified number of individuals of Vampyrum spectrum at Jenaro Herrera (see Remarks, below). IDENTIFICATION: Vampyrum, the largest bat in the Neotropics, is a monotypic genus that occurs from southern Mexico to Bolivia and southwestern Brazil (Williams and Genoways, 2008; Reid, 2009). Vampyrum spectrum can be easily distinguished from other phyllostomines by the following traits: very large size (forearm 98–118 mm, greatest length of skull 49–54 mm); large ears; tail absent; calcar longer than foot; rostrum as long as braincase; three lower premolars; and two pairs of lower incisors (Williams and Genoways, 2008; Reid, 2009; Díaz, 2011; López-Baucells et al., 2018). Descriptions and measurements of V. spectrum were provided by Goodwin and Greenhall (1961), Husson (1962, 1978), Swanepoel and Genoways (1979), Williams and Genoways (1980a), Navarro and Wilson (1982), Brosset and Charles-Dominique (1990), Simmons and Voss (1998), Vargas-Espinoza et al. (2004), Discher et al. (2009), Díaz (2011), and Sousa et al. (2011). No subspecies are currently recognized (Williams and Genoways, 2008). Vampyrum spectrum is morphologically unmistakable, so we see no reason to doubt Ascorra et al.’s (1993) identification of the individuals they captured and released at Jenaro Herrera. Their single reported forearm measurement (117 mm, from a female) is consistent with the known range of morphometric variation in this species and is much too large for the forearm of any other Neotropical bat. REMARKS: Ascorra et al. (1993) reported that at least one of the individuals they captured was caught in a mistnet, where it was feeding on a Carollia benkeithi (identified as C. castanea)., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 85, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Micronycteris (Micronycteris) microtis Miller, 1898 VOUCHER MATERIAL (TOTAL = 28): Nuevo San Juan (AMNH 272856, 273072, 273081, 273098, 273123, 273134, 273148, 273149, 273163, 273169, 273170, 273190, 273192; MUSM 13210–13212, 15218–15226, 15230, 15232, 15233); see table 28 for measurements. UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Micronycteris microtis is widely distributed from southern Mexico to northern Argentina (Williams and Genoways, 2008; Díaz and Barquez, 2009; Reid, 2009; Moras et al., 2015). Our material represents the first record of this species in Peru. Micronycteris microtis can be distinguished from other congeners by external and craniodental features including: ear M. microtis have been provided by Brosset and Charles-Dominique (1990), Simmons (1996), Simmons and Voss (1998), Lim et al. (1999), Larsen et al. (2011), and Moras et al. (2015). Two subspecies are currently recognized: M. m. mexicana (Mexico to western Costa Rica) and M. m. microtis (eastern Nicaragua to South America) (Simmons, 1996). Fleck et al. (2002) and Moras et al. (2015) correctly identified their material from Nuevo San Juan, which conforms to previous descriptions of Micronycteris microtis and has measurements that fall within the previously documented range of size variation for the species. However, one individual from this series (AMNH 273169), which has a cytochrome b genetic distance of 4.7% from Brazilian samples of M. microtis, was identified as “ M. sp.” by Porter et al. (2007), as “ M. sp.” and M. megalotis by Larsen et al. (2011), and as M. microtis and “ M. sp.” by Siles et al. (2013). These taxonomic discrepancies reflect ongoing uncertainty about species limits among the dark-bellied forms of Micronycteris. Pending resolution of these issues with more extensive sampling and additional molecular markers we recognize the Nuevo San Juan material as M. microtis based on the phenotypic data at hand. REMARKS: We captured one individual of Micronycteris microtis in a ground-level mistnet in secondary vegetation near Nuevo San Juan, but the 27 other specimens from this locality were taken from roosts (table 29). Most roosts were in tunnellike shelters (hollow logs or animal burrows), but occasionally also in cavities in standing trees; all roosts were found at or near ground level. Most roosts were in well-drained primary upland forest (typically on hill slopes or hillcrests), but one was in secondary vegetation in an old blowdown. Micronycteris microtis was usually found roosting alone, but one roost was shared with M. hirsuta, and five roosts were shared with Carollia brevicauda. Hollow logs are the commonest roost type from which this species has been reported at Amazonian localities (Voss et al., 2016)., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 61, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Family Thyropteridae Miller, 1907 The Neotropical family Thyropteridae includes a single genus with five species characterized by small size; the presence of a fleshy circular disk on the sole of each foot; a fleshy oval or circular disk attached by a short pedicle to the base of each thumb; and fusion of the soft tissues of digits III and IV of each foot to form a single conjoined structure (Simmons and Voss, 1998; Velazco et al., 2014). Velazco et al. (2014) provided a key to the species, of which four are represented in the voucher material we examined from the Yavarí-Ucayali interfluve., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 125, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Cyttarops alecto Thomas, 1913 VOUCHER MATERIAL (TOTAL = 1): Quebrada Sábalo (MUSA 15288); see table 1 for measurements. UNVOUCHERED OBSERVATIONS: See Remarks. IDENTIFICATION: Cyttarops is a monotypic genus that is easily distinguished from other emballonurids by its long, silky, smoky-gray to blackish pelage; a uropatagium bearing neither specialized sacs nor glands; a long, narrow postorbital process that is not fused to the supraorbital ridge; and by the absence of a gap between the two upper premolars (Jones and Hood, 1993; Hood and Gardner, 2008; López-Baucells et al., 2018). Descriptions and measurements of C. alecto were provided by Starrett and Casebeer (1968), Jones and Hood (1993), Hood and Gardner (2008), Velazco et al. (2011), Tavares et al. (2012), and Ludeña and Medina (2017). No subspecies are currently recognized (Hood and Gardner, 2008). Medina et al. (2015) erroneously reported the adult male specimen from Quebrada Sábalo as Centronycteris maximiliani based on external characters. Subsequent study of craniodental morphology and re-examination of the skin resulted in the correct identification (Ludeña and Medina, 2017). REMARKS: The Quebrada Sábalo specimen was captured in a mistnet suspended 22 m above ground (Medina et al., 2015). Several individuals of a small grayish bat that D.W.F. and his Matses companions flushed from the fronds of a Mauritia flexuosa palm in a palm swamp (aguajal) at Nuevo San Juan in 1999 may have belonged to this species., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on pages 12-13, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Diphylla ecaudata Spix, 1823 VOUCHER MATERIAL (TOTAL = 3): Quebrada Betilia (MUSA 15164), Quebrada Lobo (MUSA 15132), Quebrada Pantaleón (MUSA 15248). UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Diphylla ecaudata can be distinguished from other vampire species by the following characteristics: thumb small (usually D. ecaudata were provided by Swanepoel and Genoways (1979), Greenhall et al. (1984), Kwon and Gardner (2008), and Velazco and Patterson (2019). Two subspecies are currently recognized: D. e. centralis (southern US southward through eastern Mexico and Central America) and D. e. ecaudata (Venezuela, Colombia, Ecuador, Peru, Bolivia, and Brazil, with the exception of the central Amazon basin) (Greenhall et al., 1984; Kwon and Gardner, 2008). Medina et al. (2015: fig. 2D) correctly identified their specimens as belonging to the nominotypical subspecies. REMARKS: All examined specimens of Diphylla ecaudata are from the Zona Reservada Sierra del Divisor, where they were presumably taken in mistnets (Medina et al., 2015), but no other capture information is currently available to us. No roosting groups of this typically caveroosting species (Kwon and Gardner, 2008) were encountered during our fieldwork., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 40, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Artibeus (Artibeus) concolor Peters, 1865 VOUCHER MATERIAL (TOTAL = 6): Jenaro Herrera (MUSM 1321, 5513, 5514, 6967, 6968; 6970); see table 38 for measurements. UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Artibeus concolor is a widespread Amazonian species (Ascorra et al., 1993; Marques-Aguiar, 2008a). It can be distinguished from other congeners by the following combination of characteristics: medium size (forearm 43–52 mm, greatest length of skull 20.6–22.5 mm), gray-brown to brownish tricolored dorsal fur, shoulders and venter paler than dorsum, lack of facial stripes, plagiopatagium attached to leg at the base of the toes, paraoccipital processes weakly developed or absent, M1 with weakly developed hypocone, and upper and lower third molars present (Acosta and Owen, 1993; Simmons and Voss, 1998; Marques-Aguiar, 2008a; López-Baucells et al., 2018). Descriptions and measurements of A. concolor were provided by Husson (1962, 1978), Gardner (1976), Carter and Dolan (1978), Genoways and Williams (1979), Swanepoel and Genoways (1979), Handley (1987), Brosset and Charles-Dominique (1990), Acosta and Owen (1993), Simmons and Voss (1998), and Lim et al. (2005). No subspecies are currently recognized (Marques-Aguiar, 2008a). Ascorra et al. (1993) correctly identified their specimens from Jenaro Herrera, which conform to previous qualitative and morphometric descriptions of Artibeus concolor. REMARKS: No ecological information is available for Artibeus concolor in our region., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 90, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Micronycteris (Xenoctenes) hirsuta (Peters, 1869) Figure 15B VOUCHER MATERIAL (TOTAL = 6): Jenaro Herrera (ROM 122114); Nuevo San Juan (AMNH 273153; MUSM 15213–15216); see table 30 for measurements. UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Micronycteris hirsuta is a widespread species that occurs from southern Honduras to northern South America, with a disjunct population in southeastern Brazil (Williams and Genoways, 2008; Reid, 2009). Micronycteris hirsuta is easily distinguished from other congeneric species by its large size (forearm> 40 mm, greatest length of skull> 21 mm), and uniquely high-crowned but mesiodistally narrow lower incisors (Simmons et al., 2002: fig. 3 B; López-Baucells et al., 2018). Descriptions and measurements of M. hirsuta were provided by Andersen (1906a), Sanborn (1949a), Goodwin and Greenhall (1961), Swanepoel and Genoways (1979), Genoways et al. (1981), Brosset and Charles-Dominique (1990), Simmons (1996), Simmons and Voss (1998), Simmons et al. (2002), Lim et al. (2005), Fonseca et al. (2007), and Larsen et al. (2011). No subspecies are currently recognized, but a revision of the species is needed (Williams and Genoways, 2008). Fleck et al. (2002), Simmons et al. (2002), and Larsen et al. (2011) correctly identified the specimens from Nuevo San Juan as Micronycteris hirsuta. Voucher material from the Yavarí-Ucayali interfluve conforms to previous descriptions of the species, and measurements fall within the previously documented range of intraspecific size variation. REMARKS: One individual of Micronycteris hirsuta was taken in a ground-level mistnet in secondary vegetation at Jenaro Herrera on 17 January 2012, but the other specimens captured in our region were taken at roosts. We found three roosts of this species near Nuevo San Juan. The first, encountered on 13 October 1999, was a hollow standing tree at the edge of an abandoned Matses swidden; two individuals (of which one adult female was collected) were roosting about 2 m above ground level in the dark interior. The second roost, encountered on 15 October 1999, was a hollow standing tree in primary hilltop forest; three individuals (one adult male, one adult female, and one juvenile male) were roosting 4 m above the ground in the dark interior. The third roost, encountered on 20 October 1999, was a hole in the side of a stream headwater gully, about 1 m in diameter and too deep for the end to be visible; one adult female M. hirsuta and two individuals of M. microtis were collected here. Most roosts of Micronycteris hirsuta previously reported in the literature have been discovered inside hollow trees (Goodwin and Greenhall, 1961; Tuttle, 1970; Simmons and Voss, 1998)., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on pages 64-65, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Artibeus (Dermanura) glaucus Thomas, 1893 VOUCHER MATERIAL (TOTAL = 6): Jenaro Herrera (MUSM 5516, 5518), Nuevo San Juan (AMNH 272823; MUSM 13157), Quebrada Betilia (MUSA 15174), Quebrada Blanco (MUSM 21012); see table 42 for measurements. UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Artibeus glaucus is often confused with A. gnomus, but it can be distinguished from that species and other congeners by the following combination of characteristics: dark-gray to blackish dorsal pelage; tricolored dorsal fur; weakly defined white facial stripes; ear uniformly pigmented, without distinctly paler margins; entire forearm covered by long, dense fur; uropatagium dark gray and sparsely furred; rostrum short, broad, and not upturned, but with a dorsal concavity in the nasal region; posterior border of hard palate U-shaped; angular process well-developed and reaching the level of the condyloid process; second upper premolar caniniform; M1 with narrow talon; and m3 present (Handley, 1987; Marques-Aguiar, 2008a; Díaz et al., 2016; López-Baucells et al., 2018; Solari, 2019c). Descriptions and measurements of A. glaucus were provided by Andersen (1908), Davis (1970), Carter and Dolan (1978), Swanepoel and Genoways (1979), Lim et al. (2008), and Velazco and Patterson (2019). No subspecies are currently recognized (Lim et al., 2008). Ascorra et al. (1993) identified their specimens from Jenaro Herrera as Artibeus gnomus, but after reviewing these specimens we reidentified them as A. glaucus. Fleck et al. (2002) and Medina et al. (2015), however, correctly identified their specimens from Nuevo San Juan and Quebrada Betilia, respectively, as A. glaucus. All the voucher material we examined from the Yavarí-Ucayali interfluve conforms to previous descriptions of the species, with measurements that fall within the previously documented range of intraspecific size variation. REMARKS: Both individuals of Artibeus glaucus from Nuevo San Juan (the only specimens accompanied by ecological data from our region) were collected at roosts. One roost was an unmodified dead palm frond that had fallen from the canopy and was suspended horizontally about 2 m above the ground in the undergrowth of hillcrest primary forest; a single adult male was found clinging to the rachis of this frond on 30 June 1998. A second roost, encountered on the same date, was an unmodified frond of a stemless palm in the understory of primary hillcrest forest; dead leaves had accumulated on the upper surface of the frond, creating a dark place on the underside, which was occupied by two bats (of which one adult male was collected)., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 100, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Sphaeronycteris toxophyllum Peters, 1882 VOUCHER MATERIAL (TOTAL = 1): Estación Biológica Madre Selva (MUSM 32955); see table 47 for measurements. 12 Tuttle misidentified his specimens of Platyrrhinus infuscus as Vampyrops vittatus (see Koopman, 1978). UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Sphaeronycteris is a widespread monotypic genus that occurs from eastern Colombia and Venezuela southward into the western Amazon basin of Ecuador, Peru, Brazil, and Bolivia (Simmons, 2005; Angulo et al., 2008; Gardner, 2008g). Sphaeronycteris toxophyllum is easily distinguished from other stenodermatines by the presence of the following characteristics: a large, sexually dimorphic fleshy protuberance on the forehead that extends forward above the eyes and noseleaf in males (this structure is present but much smaller in females); a large fold of skin around the neck in males (present but smaller in females); and white spots on the shoulders (Angulo et al., 2008; López-Baucells et al., 2018). Descriptions and measurements of Sphaeronycteris have been provided by Husson (1958), Swanepoel and Genoways (1979), Angulo and Díaz (2004), Rodríguez-Posada and Cardenas-Gonzales (2012), and Gallardo et al. (2014). No subspecies are currently recognized (Angulo et al., 2008). The single voucher we examined (a fluid-preserved specimen) is unambiguously identifiable as Sphaeronycteris toxophyllum based on the external characters listed above and external measurements that fall within the range of size variation previously documented for this species. REMARKS: The single individual known from our region was captured in a ground-level mistnet in várzea (seasonally inundated riparian forest) about 50 m from the Río Orosa (Angulo and Díaz, 2004)., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 111, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Thyroptera lavali Pine, 1993 VOUCHER MATERIAL (TOTAL = 5): Jenaro Herrera (MUSM 5944), Quebrada Esperanza (FMNH 89118–89121); see table 56 for measurements. UNVOUCHERED OBSERVATIONS: None. IDENTIFICATION: Thyroptera lavali is distinguished from other members of the genus by the following combination of characteristics: bicolored brownish ventral pelage; proximal portion of the forearm sparsely haired; adhesive disk at base of thumb oblong; calcar with just one posterolaterally projecting lappet; foramen ovale large; outer upper incisor mesial and distal cusps subequal in size; both cusps on the outer upper incisor perpendicularly arranged relative to the long axis of the toothrow; first upper premolar circular in occlusal view; and outer lower incisor lacking accessory cusps (Velazco et al., 2014; López-Baucells et al., 2018). Descriptions and measurements of T. lavali have been provided by Pine (1993), Solari et al. (2004), Gregorin et al. (2006), and Velazco et al. (2014). No subspecies are currently recognized (Wilson, 2008a). The type series of Thyroptera lavali was comprised of four specimens from Quebrada Esperanza (Pine, 1993). Ascorra et al. (1993) identified the specimen from Jenaro Herrera as T. discifera, but Solari et al. (2004) correctly reidentified it as Thyroptera lavali. REMARKS: No ecological information is available about Thyroptera lavali in our region., Published as part of Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, pp. 1-201 in Bulletin of the American Museum of Natural History 2021 (451) on page 126, DOI: 10.1206/0003-0090.451.1.1, http://zenodo.org/record/5415316

Myotis morrisi (N = 1). ETHIOPIA ��� Blue Nile Gorge, Mouth of Didessa River, Forward Base Three (BMNH 70.488 [holotype])., Published as part of Simmons, Nancy B., Flanders, Jon, Fils, Eric Mo��se Bakwo, Parker, Guy, Jamison D. Suter,, Bamba, Seinan, Douno, Mory, Mamady Kobele Keita,, Morales, Ariadna E. & Frick, Winifred F., 2021, A new dichromatic species of Myotis (Chiroptera: Vespertilionidae) from the Nimba Mountains, Guinea, pp. 1-37 in American Museum Novitates 3963 on page 33, DOI: 10.5281/zenodo.4438059

Simmons, Nancy B., Flanders, Jon, Fils, Eric Moïse Bakwo, Parker, Guy, Jamison D. Suter,, Bamba, Seinan, Douno, Mory, Mamady Kobele Keita,, Morales, Ariadna E., Frick, Winifred F. (2021): A new dichromatic species of Myotis (Chiroptera: Vespertilionidae) from the Nimba Mountains, Guinea. American Museum Novitates 3963: 1-37, DOI: http://doi.org/10.5281/zenodo.4438059, Hdl: handle/2246/7249, URL: http://digitallibrary.amnh.org/handle/2246/7249, {"references":["Anwarali Khan, F.A., et al. 2010. Systematics of Malaysian woolly bats (Vespertilionidae: Kerivoula) inferred from mitochondrial, nuclear, karyotypic, and morphological data. Journal of Mammalogy, 91 (5): 1058-1072.","Archer, F.I., P.E. Adams, and B.B. Schneiders. 2017. strataG: an r package for manipulating, summarizing and analysing population genetic data. Molecular Ecology Resources 17 (1): 5-11.","Bhak, Y., et al. 2017. 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The smaller mammals of Kwazulu-Natal. Pietermaritzburg: University of Natal Press, 139 pp.","Taylor, P.J. 2000. Bats of southern Africa - guide to biology, identification, and conservation. Pietermaritzburg: University of Natal Press. 206 pp.","Tsytsulina, K., M.H. Dick, K. Maeda, and R. Masuda. 2012. Systematics and phylogeography of the steppe whiskered bat Myotis aurascens Kuzyakin, 1935 (Chiroptera, Vespertilionidae). Russian Journal of Theriology 11: 1-20.","Weyeneth, N., S.M. Goodman, S. and M. Ruedi. 2011. Do diversification models of Madagascar's biota explain the population structure of the endemic bat Myotis goudoti (Chiroptera: Vespertilionidae)? Journal of Biogeography, 38: 44-54.","Wieringa, J.J., and L. Poorter. 2004. Biodiversity hotspots in West Africa, patterns and causes. 61-72 In L. Poorter, F. Bongers, F.N. Kouame, and W.D. Hawthorne (editors), Biodiversity of West African forests. An ecological atlas of woody plant species. 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Myotis nimbaensis, new species Nimba Myotis Figures 3���8 HOLOTYPE: AMNH 279589, an adult male captured and released on 26 January 2018 at Kaiser Adit 3 and then collected on 2 February 2018 by Jon Flanders and Eric Mo��se Bakwo Fils at Kaiser Adit 1 (fig. 2), Nimba Mountains, Guinea (N07.66499, W008.37223), field number BCIGU133. The specimen was preserved whole in formalin and stored in ethanol, and the skull was subsequently extracted and cleaned. A 3 mm wing biopsy tissue sample was collected and stored in desiccant before the DNA was extracted at CIBIO-InBIO, University of Porto, Portugal. PARATYPE: AMNH 279590, an adult female collected at the same time and place as the holotype, field number BCIGU132. Like the holotype, the paratype was preserved in formalin and stored in ethanol after a 3 mm wing biopsy tissue sample was collected and stored in desiccant before the DNA was extracted. The skull was subsequently extracted and cleaned. OTHER RECORDS: In addition to the captures of the holotype and paratype, we recorded echolocation calls from the male holotype on 26 January 2018. Once its distinctive call parameters were identified, we searched for its echolocation call signature in sound files recorded at the entrances of 10 mine adits between 2018���2019, including the type locality, within the Nimba Mountains��� Mining Concession in Guinea (fig. 1), using Song Meter SM4BAT acoustic detectors (Wildlife Acoustics). Echolocation calls closely matching those recorded from the release calls of the holotype were detected at the entrances of a total of five mine adits (fig. 1) with seasonal variation between sites and the highest activity rates recorded at the type locality. While the Nimba Mountains support an exceptionally diverse bat fauna, this is the first Myotis species observed using the adits and only the second Myotis species to be recorded across the whole mountain range (Monadjem et al., 2016). Details of call frequency and structure, as well as comparisons with calls of congeneric species, are provided below in the section entitled Echolocation Calls. DISTRIBUTION: Known only from the type locality and vicinity in the Guinean Nimba Mountains. ETYMOLOGY: Myotis nimbaensis (���from Nimba ���) is named in recognition of the mountain range in which it was discovered. As an epithet referring to a place, nimbaensis is spelled the same way whether applied in combination with either a masculine or a feminine genus name. Woodman (1993) argued that Myotis should be considered feminine in gender, but Pritchard (1994) disagreed. Both of these authors overlooked a 1958 ruling by the International Commission on Zoological Nomenclature that fixed the gender of Myotis as masculine and placed the name as such on the Official List of Generic Names in Zoology (International Commission on Zoological Nomenclature, 1958). So in this case, nimbaensis is masculine. DIAGNOSIS AND DESCRIPTION: Myotis nimbaensis is diagnosed by a combination of the following characteristics: large size (FA 52.4���55.2 mm, mass 15.5���17.0 g; table 1) with females apparently somewhat larger than males; dorsal fur bright orange with strongly tricolored hairs (basal 1/3 of hair shaft black, middle 1/3 of shaft creamy white, distal 1/3 and tip bright orange to coppery red); ventral fur paler than dorsal fur, tricolored on belly (black base, buff-colored shaft that grades to orange at tip) grading to bicolored (lacking black base) on the sides near the wing membranes; ruff of brighter fur present around neck; pointed face with pale skin covered with orange fur, skin clearly visible through the fur around eye, mouth, and on rostrum; no black spots present on face; pinna with a rounded tip, relatively long and reaching beyond tip of nose when laid forward; pinna with strong distal emargination; skin of pinna pale orange brown becoming slightly darker near the tip, no rim of black around ear; tragus lanceolate, slightly less than half the length of the pinna; thumb brown; wing membranes strongly dichromatic black and orange, with plagiopatagium and dactylopatagium mostly black with narrow bands of orange along the metacarpals, phalanges, and across the membrane behind the forearm and upper arm; black pigmentation extends medially nearly to body and posteromedially to tibia; membrane between metacarpals I and II pale orange; propatagium pale orange; uropatagium orangish brown with orange fur on the proximal 1/3 of the dorsal surface and pale cream-colored fur on proximal 1/5 of ventral surface; no black spots on patagia; no conspicuous gland present in plagiopatagium behind humerus; pale ventral fur extends onto proximal plagiopatagium in narrow strip along body, does not extend past knee; relatively small foot with length approximately 2/5 of tibia length; foot and toes brown, with sparse long brown hairs on the dorsal surface of each toe; wing membrane essentially naked except close to the body, where it has a sparse covering of cream colored hairs on the ventral surface; wing membrane attaches to foot at base of first toe; calcar long, more than twice the length of the hind foot, runs approximately 2/3 of the length of the uropatagium border; skull large for Myotis (GLS = 19.48���19.73 mm; CIL = 18.92���18.93 mm; CBL = 18.31���18.81 mm) with globular braincase, well-defined sloping forehead, and elongated supraorbital region all contributing to the appearance of a clearly defined and elongate rostrum; rostrum with shallow medial depression in nasal region; sagittal crest moderately well developed in both sexes; lambdoid crest weakly developed in both sexes; dental formula I2/3, C1/1, P 3/3, M3/3 = 38; I1 and I2 each with a well-developed posterior cusp; upper canine robust, crown height approximately 2 �� that of P4, basal area (as seen in occlusal view) roughly equal to that of P4; anterior two premolars (P2 and P3) much smaller than last premolar (P4); P3 with less than half the basal area of P2 and shifted lingually to be partly excluded from the toothrow although still visible in lateral view; P4 large, sharply pointed, taller than M1; lower incisors each with 4 main cusps; i3 with distal accessory cuspules; p3 relatively large, approximately three quarters the basal area of p2, and fully in line in toothrow, not shifted lingually; lower molars myotodont. COMPARISONS: External and craniodental measurements for Myotis nimbaensis and other congeneric African species with which it might be confused are provided in table 1. In addition to M. nimbaensis, three other large Myotis (subgenus Chrysopteron) species with orange dorsal fur occur in Africa: M. tricolor, M. welwitschii, and M. morrisi. Descriptions and measurements of these species can be found in Hill and Morris (1971), Hill et al. (1988), Taylor (2000), and Monadjem et al. (2010); the latter work also includes color photographs and echolocation call spectrograms. Myotis nimbaensis can be easily distinguished from M. morrisi on the basis of size, with M. morrisi being smaller in all external and craniodental dimensions (table 1). The ventral pelage of M. morrisi is also different���rather than being tricolored as in M. nimbaensis, M. morrisi has unicolored dull cream white ventral fur that is tinged a faint brown on the flanks and chin. The skull and dentition of M. morrisi is very similar to that of M. nimbaensis although the braincase of M. morrisi is somewhat more globular and lacks the sagittal crest seen in M. nimbaensis. a Holotype, AMNH 279589. HF and Ear measurements were taken after preservation. Additional measurement taken in the field: Tibia 22.35, Tragus 9.61. b Paratype, AMNH 279590. HF and Ear measurements were taken after preservation. Additional measurement taken in the field: Tibia 23.28, Tragus 10.62. c Holotype, BMNH 70.488. d AMNH 232029, 232030, 257053; BMNH 14.5.4.2, 64.172, 75.2550, 75.2551, 75.2554, 87.1082; USNM 317927, 317928, 342645, 351061. e AMNH 146789, 257358; BMNH 40.740, 40.741, 75.2549, 75.2552, 75.2553, 75.2555; USNM 292066, 238099, 342634, 242644, 351060. f BMNH 22.12.17.75. g BMNH 22.12.17.76. Myotis nimbaensis is similar in size and general coloration to the widespread species M. welwitschii, but these taxa can be easily distinguished because M. nimbaensis completely lacks the prominent black spots seen on the face and patagia of M. welwitschii (figs. 3���6). Color of the pinnae is also different���bright orange to coppery red with a black edge in M. welwitschii compared to pale orange brown with no black edge in M. nimbaensis. The thumb in M. welwitschii is bright orange whereas it is brown in M. nimbaensis. Both species are strongly dichromatic with black wing membranes and orange along the digits and forearm, but pigmentation of the plagiopatagium near the body and hind legs is different in the two species. Myotis welwitschii has a broad band of orange along the side of the body that extends anteriorly past the elbow to run along the forearm and posteriorly to the ankle, so black pigmentation is limited to the more distal and posterior portions of the plagiopatagium. In contrast, the orange is much less extensive and the black is more extensive in M. nimbaensis; the black pigmentation approaches the body wall, extending anteriorly into the plagiopatagium behind the humerus and posteriorly to the tibia in M. nimbaensis, so there is no broad band of orange along the body in that species. The uropatagium in M. welwitschii is also bright orange whereas it is darker and more brownish in M. nimbaensis. There are additional differences in features of the dorsal and ventral pelage���the dorsal fur in M. welwitschii is bicolored (black at base and otherwise coppery red) rather than being tricolored as in M. nimbaensis, and M. welwitschii has unicolored ventral pelage (whitish tinged with coppery red) rather than the distinctive tricolored ventral fur in seen in M. nimbaensis. Craniodental measurements (table 1) suggest overall similarity of M. nimbaensis with M. welwitschii; small differences in a few dimensions are not interpretable given the small sample sizes. Both species have lambdoidal crests that are weakly developed but clearly visible, and moderately well-developed sagittal crests in both sexes. The dentition of M. welwitschii includes two very small anterior upper premolars that are both included in the toothrow; P3 is smaller than P2, but P3 is not displaced lingually as it is in M. nimbaensis. Myotis tricolor is a widespread species that shows considerable morphometric variation across its range (Koopman, 1989, 1994; Taylor, 2000; Monadjem et al., 2010). Myotis nimbaensis is roughly equivalent in overall size (e.g., forearm length and body mass) to the largest individuals of M. tricolor reported in the literature, although none of the specimens of M. tricolor that we measured were as large as M. nimbaensis. The only known specimen of M. tricolor from West Africa���a male from Liberia referred to that species by Koopman (1989) ���is much smaller than M. nimbaensis, having a forearm length of 46.0 mm compared to 52.4 mm for the male paratype of M. nimbaensis. The pelage of M. tricolor is similar to that of M. nimbaensis, and M. tricolor similarly lacks black spots on the face or tail membrane. However, these species can be distinguished easily based on coloration of the wing membranes: M. tricolor has wings that are dark brown rather than the distinctive dichromatic orange and black wings seen in M. nimbaensis. The pinnae of M. tricolor are dark brown compared with the pale orange brown seen in M. nimbaensis, and the emargination is more proximally located (nearly at the midpoint of the lateral edge of the pinna) in M. tricolor compared to the clearly distal location of the emargination in M. nimbaensis. The uropatagium of M. tricolor is also darker brown (rather than orange brown as in M. nimbaensis) and has a dense covering of coppery red fur proximately (more sparse in M. nimbaensis). In terms of craniodental features, M. nimbaensis has a greater condylobasal length (18.9 mm for both sexes) than seen in M. tricolor (15.9���18.5 mm including data from table 1 and Monadjem et al., 2010). Although our comparative sample of M. tricolor was not large, we found that most other craniodental measurements similarly appear to distinguish M. nimbaensis and M. tricolor, with M. nimbaensis the larger of the two species. Sagittal crest development in Myotis tricolor is variable, with females typically lacking any sagittal crest development. In contrast, both male and female M. nimbaensis have well-developed sagittal crests (though again, our sample size is small). Upper premolars in M. tricolor are somewhat variable, but P3 is always less than half the basal area of P2 and is always shifted lingually as in M. nimbaensis. However, in many individuals the reduction in P3 is greater than in M. nimbaensis, and this tooth is completely excluded from the toothrow (only partly excluded in M. nimbaensis). The p3 of M. tricolor is one half to two thirds the basal area of p2, and p3 is sometimes displaced lingually from the toothrow, compared to a slightly larger p3 that is at least three quarters the size of p2 and which is not displaced in M. nimbaensis. Another orange Myotis species from Africa is M. bocagii, which occurs across much of tropical Africa and is broadly sympatric with M. tricolor and M. welwitschii (Monadjem and Jacobs, 2017a; Patterson, 2019). Myotis bocagii can be easily distinguished from M. nimbaensis based on its dark brown wings and considerably smaller size in all dimensions (e.g., FA = 36.0��� 40.5 mm; mass = 6.0���9.0 g.; CBL = 13.0���15.0 mm; CIL = 14.0��� 15.2 mm; Koopman, 1994; Monadjem et al., 2010). Myotis (subgenus Chrysopteron) species with yellow or orange dorsal fur and dichromatic orange and black wings are not limited to Africa, but also occur in Asia. At least six Asian species (M. bartelsi, M. formosus, M. hermani, M. rufoniger, M. rufopictus, and M. weberi) exhibit color patterns with dichromatic wing pigmentation superficially similar to that of M. nimbaensis (Csorba et al., 2014). Csorba et al. (2014) gave diagnoses and measurements of these species that provide a basis for distinguishing them from M. nimbaensis. These authors recognized two pelage and skin color patterns among the Asian species: a ��� rufoniger type ��� and a ��� formosus type.��� Species exhibiting ��� rufoniger type ��� morphology include M. bartelsi, M. hermani, M. rufoniger, and M. weberi. These species can be distinguished from M. nimbaensis based on darker dorsal pelage that has four bands of color (individual dorsal hairs black basally, pale yellow distally, then darkening to deep red before terminating in a black tip; Csorba et al., 2014) rather than the bright orange tricolored dorsal fur of M. nimbaensis. Species with ��� rufoniger type ��� coloration are also considerably darker ventrally than M. nimbaensis, having hairs with a black base, followed by either a pale yellowish section that progressively darkens distally to deep red, or are otherwise entirely deep red (Csorba et al., 2014). The ear is also edged with black in rufoniger - type species (Csorba et al., 2014), a trait lacking in M. nimbaensis (or any other African species of Chrysopteron). The thumb and underside of hind foot are entirely black in species with ��� rufoniger type ��� coloration (Csorba et al., 2014) but not in M. nimbaensis, which has an orange-brown thumb and a brown foot. Myotis rufoniger has flight membranes with a broad band of red that extends from the ankle to the forearm along the side of the body, and black pigmentation is limited to the more distal and posterior portions of the plagiopatagium (Bhak et al., 2017). In contrast, the black pigment is more extensive in M. nimbaensis, extending much closer to the body including reaching the tibia and into the membrane behind the humerus, and the pale portions of the wings are more orange than red. Members of the Myotis rufoniger group vary somewhat in size, but they are all large bats roughly comparable in size to M. nimbaensis. Measured forearm lengths of M. rufoniger (FA = 45.0���56.0; Csorba et al., 2014) overlap with those of M. nimbaensis, but cranial dimensions of M. rufoniger (e.g., GLS = 16.98���19.24 mm; ZB = 10.04���12.24 mm) do not overlap, with M. nimbaensis being the slightly larger species. Dental morphology is also somewhat different; M. rufoniger has a P3 that is roughly two thirds the size of P2 and which is usually in line with the other check teeth (rarely displaced lingually; Csorba et al., 2014), compared with M. nimbaensis, in which P3 is less than half the size of P2 and is lingually displaced. Considerable overlap in most dimensions exists between M. nimbaensis and M. weberi (FA = 49.7���53.5 mm; GLS = 19.15���19.72 mm; ZB = 12.37���12.67 mm; Csorba et al., 2014). However, M. weberi as described by Csorba et al. (2014) can be distinguished by having a relatively short upper canine that is only about 1.5 �� the height of P4 (C height is ~2 �� height of P 4 in M. nimbaensis) and a p3 that is no more than half the basal area of p2 (p3 is at least three quarters the basal area of p 2 in M. nimbaensis). In contrast to Myotis rufoniger and M. weberi, both M. bartelsi (FA = 53.4 mm; GLS = 20.42 mm; ZB = 13.41 mm) and M. hermani (FA = 56.0���60.0 mm; GLS = 20.10���21.77 mm; ZB = 13.4���14.10 mm) are somewhat larger than M. nimbaensis in most dimensions (Csorba et al., 2014). As described by Csorba et al. (2014), M. bartelsi can be distinguished by having strong lambdoid crests (weakly developed in M. nimbaensis) and a P3 that is fully out of line with the rest of the toothrow and not visible in lateral view (partially out of line and visible in lateral view in M. nimbaensis). The forehead is also less clearly developed and strongly sloped in M. bartelsi compared to M. nimbaensis, and the rostrum appears somewhat shorter in M. bartelsi in lateral view. Myotis hermani as described by Csorba et al. (2014) can be distinguished by its overall very robust skull and exceptionally well-developed sagittal and lambdoid crests (more weakly developed in M. nimbaensis), very large upper canine with a basal area exceeding that of P4 (basal areas of C and P4 subequal in M. nimbaensis), minute P3 less than one quarter the size of P2 (P3 only slightly less than one half the size of P 2 in M. nimbaensis), P3 fully out of line with the rest of the toothrow and not visible in lateral view (only partially out of line and visible in lateral view in M. nimbaensis, Published as part of Simmons, Nancy B., Flanders, Jon, Fils, Eric Mo��se Bakwo, Parker, Guy, Jamison D. Suter,, Bamba, Seinan, Douno, Mory, Mamady Kobele Keita,, Morales, Ariadna E. & Frick, Winifred F., 2021, A new dichromatic species of Myotis (Chiroptera: Vespertilionidae) from the Nimba Mountains, Guinea, pp. 1-37 in American Museum Novitates 3963 on pages 8-21, DOI: 10.5281/zenodo.4438059, {"references":["Monadjem, A., L. Richards, and C. Denys. 2016. An African bat hotspot: the exceptional importance of Mount Nimba for bat diversity. Acta Chiropterologica 18 (2): 359 - 375.","Woodman, N. 1993. The correct gender of mammalian generic names ending in - otis. Journal of Mammalogy 74 (3): 544 - 546.","Pritchard, P. C. H. 1994. Comment on the gender and declension of generic names. Journal of Mammalogy 75: 549 - 550.","International Commission on Zoological Nomenclature. 1958. Official list of generic names in zoology. London: International Trust for Zoological Nomenclature, London, 200 pp.","Hill, J. E., D. L. Harrison, and T. S. Jones. 1988. New records of bats (Microchiroptera) from Nigeria. Mammalia 52 (4): 590 - 592.","Taylor, P. J. 2000. Bats of southern Africa - guide to biology, identification, and conservation. Pietermaritzburg: University of Natal Press. 206 pp.","Monadjem, A., P. J. Taylor, W. Cotterill, and M. C. Schoeman. 2010. Bats of Southern and Central Africa. Johannesburg: Wits University Press. 596 pp.","Koopman, K. F. 1989. Systematic notes on Liberian bats. American Museum Novitates 2946: 1 - 11.","Koopman, K. F. 1994. Chiroptera: systematics. Handbuch der Zoologie, vol. 8 (Mammalia), pt. 60: 217 pp.","Patterson, B. D., et al. 2019. Genetic variation and relationships among Afrotropical species of Myotis (Chiroptera: Vespertilionidae). Journal of Mammalogy 100 (4): 1130 - 1143.","Csorba, G., et al. 2014. The reds and the yellows: a review of Asian Chrysopteron Jentink, 1910 (Chiroptera: Vespertilionidae: Myotis). Journal of Mammalogy 95 (4): 663 - 678.","Bhak, Y., et al. 2017. Myotis rufoniger genome sequence and analyses: M. rufoniger ' s genomic feature and the decreasing effective population size of Myotis bats. PloS One 12 (7).","Collen, A. 2012. The evolution of echolocation: a comparative approach. Ph. D. dissertation, Division of Biosciences, University College London, London, UK.","Monadjem, A., and D. K. Jacobs. 2017 a. Myotis bocagii. The IUCN Red List of Threatened Species 2017: e. T 14148 A 22059585.","Monadjem A, L. Richards, P. J. Taylor, and S. Stoffberg. 2013. High diversity of pipistrelloid bats (Vespertilionidae: Hypsugo, Neoromicia, and Pipistrellus) in a West African rainforest with the description of a new species. Zoological Journal of the Linnean Society 167 (1): 191 - 207."]}

Myotis tricolor (N = 28). ETHIOPIA ��� Amhara Region, Agew Awi Zone, Dangila (BMNH 37.2.24.13); KENYA���Rift Valley Province, 20 mi. SW of Kitale, R. Barberton Farm (USNM 351060, 351061); Rift Valley Province, Crater of Mt. Menengai, 7400 ft. (USNM 317927, 317928); Rift Valley Province, 3mi NW Nakuru, Menengai Crater, 6500 ft. (BMNH 75.2549 ��� 75.2554); Rift Valley Province, West Pokot County, Sigor, Wei-Wei River (BMNH 75.2555); LIBERIA ��� Grand Cape Mt., Bomi wood concession (AMNH 257053); MALAWI���Zomba District, Zomba (BMNH 87.1082); SOUTH AFRICA���Eastern Cape Province, King William���s Town (AMNH 146789); KwaZulu-Natal, Estcourt, Will Brook (BMNH 14.5.4.2); KwaZulu- Natal, Otto���s Bluff (AMNH 232029, 232030); KwaNatal, Pietermaritzburg, Town Bush (USNM 292066); Mpumalanga Provence, Barberton, Louws Creek [= Low���s Creek] (USNM 238099); Transvaal, 32 mi W of Pretoria, Uitkomst Farm (USNM 342643���342645); Transvaal, Kruger National Park, ca. 4 km east of Skukuza (AMNH 257358); UGANDA���Sebai District, Near Sipi, Cave at Kyema (BMNH 64.172); Mt. Elgon, Kapretwa (BMNH 40.740, 40.741); ZAMBIA���Cave near Mujimbe Hill (AMNH 89776)., Published as part of Simmons, Nancy B., Flanders, Jon, Fils, Eric Mo��se Bakwo, Parker, Guy, Jamison D. Suter,, Bamba, Seinan, Douno, Mory, Mamady Kobele Keita,, Morales, Ariadna E. & Frick, Winifred F., 2021, A new dichromatic species of Myotis (Chiroptera: Vespertilionidae) from the Nimba Mountains, Guinea, pp. 1-37 in American Museum Novitates 3963 on page 33, DOI: 10.5281/zenodo.4438059

Myotis nimbaensis (N = 2). GUINEA ��� Nimba Mountains, Kaiser Adit 2, N07.66499, W008.37223 (AMNH 279589 [holotype], 279590 [paratype])., Published as part of Simmons, Nancy B., Flanders, Jon, Fils, Eric Mo��se Bakwo, Parker, Guy, Jamison D. Suter,, Bamba, Seinan, Douno, Mory, Mamady Kobele Keita,, Morales, Ariadna E. & Frick, Winifred F., 2021, A new dichromatic species of Myotis (Chiroptera: Vespertilionidae) from the Nimba Mountains, Guinea, pp. 1-37 in American Museum Novitates 3963 on page 33, DOI: 10.5281/zenodo.4438059

Furipteridae Furipterus horrens: Panama: 20 km SW of Changuinola (USNM 315737); Bocas Del Toro (USNM 315734); Guyana: Cuyuni-Mazaruni, Kartabo Point, Cuyuni River (AMNH 142903); Kartabo, Bartica (AMNH 42343, 42457); French Guiana: Paracou, near Sinnamary (AMNH 267214, 265975, 265979, 267212, 267214, 267507, 268572–73); Saint Laurent Du Maroni, Road to Belizon, gold mine (AMNH 244493, CT image); Brazil: Pará, Rio Xingu (USNM 549507); Brazil, Pará, Altamira, 50 km SSW, Island in Rio Xingu (Ilha Jabuti, (USNM 549598)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 140, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Phyllostomidae Macrotus waterhousii: Mexico: Jalisco, Bolaño (AMNH 2003); Morelos, Lago de Tequesquitengo, Cueva del Cerro (USNM 559490–91); Nayarit, Islas Tres Marias, Maria Madre (AMNH 180523); Oaxaca, Tehuantepec, Santo Domingo Tehuantepec, Mount San Pedro, Arroyo Ocotita (AMNH 182158); Oaxaca, Tehuantepec, Tequisistlan (AMNH 178755); Oaxaca, Tehuantepec (AMNH 171591); Dominican Republic: Caves near River Charon, E La Romana (AMNH 120975); near San Juan Bay, Rolla Seco (AMNH 91314); Haiti: Nord, Don Don (UF-M 20816); Sud, 1 mi S Duchity (7 km S Beaumont) (AMNH 236657–58); Cuba: Maranzos, near Cidra (AMNH 61161); Jamaica: Clarendon, Mahoe Gardens, Portland Cave (USNM 511232–33); St. Catherine, Healthshire Hills (AMNH 268068); St. Elizabeth, Balaclava, Oxford Cave (AMNH 45229); St. Elizabeth, Hounslow; Money Cave (AMNH 268071); Trelawny, 1 km E Quick Step (USMN 511230); Trelawny, Windsor (AMNH 45230–31); Cayman Islands: Grand Cayman, 1 km E Spots (USNM 538120, 538127). Macrotus californicus: United States: Arizona (USNM 314679); Pima, 4 mi WNW Arivaca (AMNH 170823, 170826); California, Imperial, 3 mi N Potholes (AMNH 139575–78); Mexico: Sonora, Isla Tiburon (USNM 513814, 513816). Artibeus jamaicensis: Mexico: Chiapas, 15 mi SE Mapastepec (by road) (AMNH 251657–58); Jalisco, 2.3 mi SW (by road) Le Cuesta (AMNH 254662); Oaxaca, Tapanatepec (AMNH 177744); Vera Cruz, 1 mi SE Oja de Agua (AMNH 254669); Yucantan, Chichen Itza (AMNH 91236); Yucatán, Sobre La Cairetera a Tixkokof (AMNH 204983); Panama: Canal Zone, Rodman (AMNH 213402); Venezuela: El Enoatado (AMNH 135159); Ecuador: Oriente, San Jose (AMNH 67920–21); Brazil: Par á, Rio Tocantins, Iles do Tavina (AMNH 97036–37); Bolivia: La Paz, 6.6 road km downstream Caranaui, Rio Coraica Valley (AMNH 246641, 246644); Barbados: 10 mi E Bridge Town, Chancery Lane (AMNH 239927) United States: Puerto Rico, Ponce (AMNH 119631); Puerto Rico, Utuado (AMNH 39117–18); St. Croix, Cane Bay (AMNH 214228); Jamaica: Cambridge (AMNH 45170); St. Mary, 2 mi W Port Maria (AMNH 219170)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 139, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Thyropteridae Thyroptera tricolor: Panama: Canal Zone, Barro Colorado Island (USNM 582082); Colombia: Magdelena, Santa Marta, Colonia Agricola De Caracolicito (USNM 281200); Magdalena, Santa Marta, Colonia Agricola De Caracolicito, Rio Ariguanicito (USNM 281939); Valle del Cauca (AMNH 239085); Ecuador: Tungurahua, Banos de Agua Santa (AMNH 67592); Peru: Río Amazonas, Orosa (AMNH 74024); Río Apayacu (AMNH 74377); French Guiana: Paracou, near Sinnamary (AMNH 266348, 266353, 266355–59, 266361, 266363–65,267215, 268575–76)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 140, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Noctilionidae Noctilio leporinus: Mexico: Sinaloa / Nayarit border, Rio Canas (MSB 24706); Panama: Canal Zone, Chagres River (AMNH 173912); Colombia: Rio Guaimaral (USNM 281311); Brazil: Amazonas, Rio Madiera (AMHH 91937); Amazonas, Rio Madiera, Auara Igarapé (AMNH 91960–75, 91980); Pará, Fero (AMNH 93803); Pará, Rio Tocantins, Ilha do Taiuna (AMNH 96930); Peru: Amazonas, Rio Amazonas, Pt. Indiana (AMNH 93932, 93970); Pacso, Oxapampa, San Juan (AMNH 230105, 230108– 09); Pasco, Oxapampa, San Pablo (AMNH 230110–12); Bolivia: Beni, ca. 23 km W San Javier (AMNH 210598); Cochabamba, Jodoe Santoe (AMNH 38562); Paraguay: Boqueron, Pozo Colorado (trans-Chaco route, km 250) (AMNH 234277); Trinidad and Tobago: North Manzanilla (AMNH 175534); United States: Puerto Rico, Humacao, Old Loiza (AMNH 39574, 39587); St. Kitts-Nevis: Nelson Spring (AMNH 246993). Noctilio albiventris: Colombia: Amazonas, Leticia (AMNH 207772, 207774); Río Cauca (AMNH 269200); Valle del Cauca, Ingenio de Mayagüez (AMNH 269228); Brazil: Amazonas, Rio Madeira, Auarer Igarapé (AMNH 92019– 30); Amazonas, Rio Negro, near Manaus (AMNH 79626, 79632); Amazonas, Rio Amazonas, Villa Bella Imperatriz (AMNH 92998); Peru: Oxapampa, San Pablo (AMNH 23102); Bolivia: Beni, Cercado, ca. 23 kilometers west of San Javier, Mamore River (AMNH 210576, 210595, 210624); Beni, 5 km S Guyarmarin (AMNH 209254); Paraguay: Olempo XVI, Feurte Olempo (AMNH 234256–66)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 140, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Pteronotus macleayii Pteronotus macleayii macleayii: Cuba: Habana, Bucaranao (AMNH 174250); Oriente, Baracoa (USNM 113771); Oriente, Baracoa, Cueva de Mojana (AMNH 61151–53); Pinar del Rio, San Vicente (AMNH 17618–88). Pteronotus macleayii grisea: Jamaica: Hanover, Lucea (AMNH 12359); St. Elizabeth, Balaclava, Oxford Cave (AMNH 45256, 45268–75); St. James, Montego Bay (AMNH 12390, 60917, 60896, 60899, 60902, USNM 260730); Montego Bay, Providence Cave (AMNH 34884–86, 45257– 67); Trelawny, Windsor (AMNH 61022)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on pages 137-138, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Mormoops blainvillei Mormoops blainvillei: [no data] (AMNH 213889); United States: Puerto Rico, Mona Island (AMNH 72547); Puerto Rico, Trujillo Alto, Cueva de Trujillo Alto (AMNH 72370); Cuba: [no additional information] (AMNH 213889); Barbacoa (USNM 113766); Oriente, Siboney, Cueva de Los Majaes (AMNH 176149– 50); Pinar del Rio, San Vincente, Cueva del Indio (AMNH 176139); Santiago de Cuba, Cueva de los Majaes (MSB 66629); Dominican Republic: Barahano, Pedernales, Cabo Rio (AMNH 238144); San Cristobal, Cueva La Chepa, 10 km N Bayaguana (USNM 535251); San Rafael, Rancho la Guardia (AMNH 213897); Jamaica: St. Catherine, St. Clair (AMNH 246123); St. Elizabeth, Balaclava, Oxford Cave (AMNH 45197– 205); Trelawny Parish, Quick Step (USNM 511225–27, 545146)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 139, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Emballonuridae Saccopteryx bilineata: Mexico: Colima, Man- zanillo, 4 kilometers east northeast of Manza- nillo, Ejido Tepextiles (AMNH 172063); Oaxaca, Mixe, San Juan Mazatlan (AMNH 175300–01); Oaxaca, Mixe, San Juan Cotzocon, Nueva Raza (AMNH 178776–77); Guatemala, Tikal, Petén (UF-M 6971); Costa Rica: Heredia, Finca La Selva (MSB 34210); Puntarenas, Palmer (Pacific) (AMNH 139449); Panama: Canal Zone, Gatun Lake (USNM 514986); Chilibrillo Caves (USNM 306471); Guyana: Rupununi District, 15 mi E Dadanawa (USNM 338917); French Guiana: Paracou, near Sinnamary (AMNH 267060, 267064, 267377); Brazil: Pará, Altamira, 52 km SSW, E Bank Rio Xingu (USNM 549311); Rio Madeira, Rosarinho (AMNH 92657, 92661); Bolivia: Beni, 5 km NW Grande river mouth (AMNH 210469)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 141, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Emballonuridae Saccopteryx bilineata: Mexico: Colima, Man- zanillo, 4 kilometers east northeast of Manza- nillo, Ejido Tepextiles (AMNH 172063); Oaxaca, Mixe, San Juan Mazatlan (AMNH 175300–01); Oaxaca, Mixe, San Juan Cotzocon, Nueva Raza (AMNH 178776–77); Guatemala, Tikal, Petén (UF-M 6971); Costa Rica: Heredia, Finca La Selva (MSB 34210); Puntarenas, Palmer (Pacific) (AMNH 139449); Panama: Canal Zone, Gatun Lake (USNM 514986); Chilibrillo Caves (USNM 306471); Guyana: Rupununi District, 15 mi E Dadanawa (USNM 338917); French Guiana: Paracou, near Sinnamary (AMNH 267060, 267064, 267377); Brazil: Pará, Altamira, 52 km SSW, E Bank Rio Xingu (USNM 549311); Rio Madeira, Rosarinho (AMNH 92657, 92661); Bolivia: Beni, 5 km NW Grande river mouth (AMNH 210469).

Koopmanycteris palaeomormoops, gen. et sp. nov. Figures 2–13 HOLOTYPE: UF 157765, right dentary with p4–m3 and alveoli for i1–p3, from Brooksville 2 LF, early Arikareean, Hernando County, Florida. PARATYPES: All specimens are from the Brooksville 2 LF. SCSM 2004.35.1, partial right dentary with m1–m3 and complete ascending ramus; UF 209954, right dentary fragment with p3 and alveoli for i1–p1; UF 182782, leπ P4; UF 179949, complete leπ humerus; UF 179922, leπ proximal radius; UF 179948, leπ proximal femur; UF 179947, right distal femur. REFERRED SPECIMENS: Brooksville 2 Local Fauna: UF 179985, partial right dentary with p4– m2; UF 179951, partial right dentary with p4, m2 and alveoli for c–p3, m1; UF 157767, partial leπ dentary with m1–m2; SCSM 2004.35.2, leπ dentary fragment with m1–m2; UF 157766, partial right dentary with m2–m3, including most of the ascending ramus except for the tip of the coronoid process; SCSM 2004.35.3, partial leπ dentary with m3 and complete ascending ramus; SCSM 2004.35.4, partial right dentary with p3; UF 179957, edentulous leπ dentary with partial ascending ramus; UF 179990, UF 182816, right m1 (2); UF 182815, leπ m1; UF 182810, right m2; UF 179901, right petrosal; UF 179937, right proximal humerus; SCSM 2004.35.5, leπ proximal humerus; UF 179907, 179908, 179938; right distal humerus (3); UF 179905, 179906, leπ distal humerus (2); UF 179917 –179919, 1179941, right proximal radius (4); UF 179916, 179920, 179921, 179923–179925, 179943, 179970, 179973, 209955, left proximal radius (10); SCSM 2004.35.6, leπ proximal femur. I-75 Local Fauna: UF 121718, partial leπ dentary with p4, trigonid of m1, and alveolus for p3; UF 121719, partial leπ dentary with p4 and alveoli for i2–p3; UF 121720, partial right dentary with m1 and alveoli for p3–p4; UF 121733, edentulous partial leπ dentary with alveoli for m2– m3 and anterior edge of ascending ramus; UF 121721, leπ proximal femur; UF 121722, right proximal femur. TYPE LOCALITY: Brooksville 2 Local Fauna, Hernando County, Florida, late early Arikareean (Ar2), late Oligocene. ETYMOLOGY: The generic epithet derives from Koopman, in honor of the late Karl F. Koopman, formerly of the American Museum of Natural History, in recognition of his monumental contributions to our knowledge of the systematics, evolution, and biogeography of the Chiroptera, and nycteris, Greek meaning “bat.” The specific epithet is composed of palaeos, Greek for “ancient” or “old,” mormo, Greek for a kind of nighttime monster or ghost, and ops, Greek for “face.”The species name “ palaeomormoops ” or “ancient ghost face” alludes to this species being the oldest known member of the ghost-faced bat family Mormoopidae, and also indicates its phylogenetic relationship with the extant genus Mormoops. DIAGNOSIS: Lower p3 large, double rooted, outline in occlusal view diamond shaped, with anterior portion of tooth rounded and posterior portion pointed. Lower p4 squarish to slightly rectangular in occlusal view, somewhat narrower anteriorly than posteriorly, with well-developed cingulum on anterior, labial, and posterior margins, but with cingular development weak to absent on the lingual margin. Lower m1 and m2 nyctalodont. Paraconid on m1 highly reduced, positioned labially about halfway between protoconid and metaconid. Metaconid on m1 and m2 taller than entoconid. Dentary with ascending ramus strongly upturned dorsally compared to horizontal ramus; angular process and articular condyle both located well dorsal to alveolar margin of toothrow; coronoid process with its anterior edge essentially vertical; articular condyle located well dorsal to tip of coronoid process; small secondary process present on ascending ramus immediately ventral to angular process. Upper P4 with large, rounded anterior basin, broad talon basin, and tall, sharp central cusp (protocone). Proximal humerus with head elliptical in shape, transversely flattened and directed proximally, and angled toward lesser trochanter. Distal humerus with articular surface moderately offset laterally from humeral shaπ; capitulum not differentiated into medial and lateral ridges; well-developed spinous process separated from medial edge of trochlea by deep notch; epitrochlea a well-developed rounded process with small concavity at proximomedial corner. Proximal end of radius gently rounded, not triangular. Proximal articular surface of radius with two articular facets. Femur with greater trochanter and lesser trochanter highly reduced; greater trochanter larger than lesser trochanter and triangular in shape. Distinct tubercle or short ridge present on posterodistal femoral shaft just proximal to distal articular surface. Femur comparatively long, more than three times longer than alveolar length of toothrow., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on pages 12-13, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Pteronotus quadridens Pteronotus quadridens fuliginosus: United States: Puerto Rico, San Juan, Pueblo Viejo, Cueva de Fari (AMNH 39353–59, 39363–67); Trujillo Alto (39396–03); Dominican Republic: between Cabra and Nagua, Cueva de Murcielagos (AMNH 238138); La Altagracia, Boca de Yuma (AMNH 238139); Santo Domingo, Cana Honda (AMNH 25760); Haiti: Cerca La Source (USNM 253631–32); Sud, Sapoti (19 km SW Beaumont) (AMNH 236654); Jamaica: St. Elizabeth, Balaclava, Oxford Cave (AMNH 45248– 55); St. Elizabeth, Accompong Town (UF-M 12684). Pteronotus quadridens torrei: Cuba: [no additional information] (AMNH 60637–38); Oriente, 8 mi E Baracoa (USNM 113786, 121061); La Habana, Bararanao, Cueva de El Fantasma (AMNH 176061); Las Villo, Punta Caquanes, Yaguajay “Cueva de Colon” (AMNH 186970–71). Pteronotus personatus species group Pteronotus psilotis: Mexico: Colima, Ixtlahuacán, 1.6 km NE Las Conchas (OMNH 27773); Colima, Manzanillo, Playa de Oro, Cueva la Murcielaguera (OMNH 38769); Morelos, Tequesquitengo (AMNH 180443–44, 180446); Nayarit, Nayarit-Sinaloa state line, Rio Canas, near la Concha (USNM 508415); Oaxaca, Juchitan, Tapanatpec (AMNH 175018–19, 177672–93, 177695–96, 178468); Sonora, La Aduana (MSB 55419); Vera Cruz, Agua Fria (MSB 75556). Pteronotus personatus: Colombia: Bolivar ( USNM 430190, 433531); Bolivar, Cartagena (USNM 433517, 433531); Panama: San Blas, Armila (Quebrada Venado) (USNM 335085–86); Venezuela: Sucre, La Brea (AMNH 33300); Yara- cui, Aroa, Bolivar R.R. (33112, 32123–24, 32127– 32133, 32136–37); Trinidad and Tobago: St. George, Tacariquas; St. Augustine (AMNH 175560)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 138, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Mystacinidae Mystacina robusta: New Zealand: Stewart Island (AMNH 160269); island off SW of Stewart Island (AMNH 214243). Mystacina tuberculata: New Zealand: [no additional data] (MNHN 1983.1464; MVZ 174825); North Island, Omahuta Kauri Forest (MVZ 173919; ROM 80308)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on pages 140-141, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Koopmanycteris palaeomormoops, gen. et sp. nov. Figures 2–13 HOLOTYPE: UF 157765, right dentary with p4–m3 and alveoli for i1–p3, from Brooksville 2 LF, early Arikareean, Hernando County, Florida. PARATYPES: All specimens are from the Brooksville 2 LF. SCSM 2004.35.1, partial right dentary with m1–m3 and complete ascending ramus; UF 209954, right dentary fragment with p3 and alveoli for i1–p1; UF 182782, leπ P4; UF 179949, complete leπ humerus; UF 179922, leπ proximal radius; UF 179948, leπ proximal femur; UF 179947, right distal femur. REFERRED SPECIMENS: Brooksville 2 Local Fauna: UF 179985, partial right dentary with p4– m2; UF 179951, partial right dentary with p4, m2 and alveoli for c–p3, m1; UF 157767, partial leπ dentary with m1–m2; SCSM 2004.35.2, leπ dentary fragment with m1–m2; UF 157766, partial right dentary with m2–m3, including most of the ascending ramus except for the tip of the coronoid process; SCSM 2004.35.3, partial leπ dentary with m3 and complete ascending ramus; SCSM 2004.35.4, partial right dentary with p3; UF 179957, edentulous leπ dentary with partial ascending ramus; UF 179990, UF 182816, right m1 (2); UF 182815, leπ m1; UF 182810, right m2; UF 179901, right petrosal; UF 179937, right proximal humerus; SCSM 2004.35.5, leπ proximal humerus; UF 179907, 179908, 179938; right distal humerus (3); UF 179905, 179906, leπ distal humerus (2); UF 179917 –179919, 1179941, right proximal radius (4); UF 179916, 179920, 179921, 179923–179925, 179943, 179970, 179973, 209955, left proximal radius (10); SCSM 2004.35.6, leπ proximal femur. I-75 Local Fauna: UF 121718, partial leπ dentary with p4, trigonid of m1, and alveolus for p3; UF 121719, partial leπ dentary with p4 and alveoli for i2–p3; UF 121720, partial right dentary with m1 and alveoli for p3–p4; UF 121733, edentulous partial leπ dentary with alveoli for m2– m3 and anterior edge of ascending ramus; UF 121721, leπ proximal femur; UF 121722, right proximal femur. TYPE LOCALITY: Brooksville 2 Local Fauna, Hernando County, Florida, late early Arikareean (Ar2), late Oligocene. ETYMOLOGY: The generic epithet derives from Koopman, in honor of the late Karl F. Koopman, formerly of the American Museum of Natural History, in recognition of his monumental contributions to our knowledge of the systematics, evolution, and biogeography of the Chiroptera, and nycteris, Greek meaning “bat.” The specific epithet is composed of palaeos, Greek for “ancient” or “old,” mormo, Greek for a kind of nighttime monster or ghost, and ops, Greek for “face.”The species name “ palaeomormoops ” or “ancient ghost face” alludes to this species being the oldest known member of the ghost-faced bat family Mormoopidae, and also indicates its phylogenetic relationship with the extant genus Mormoops. DIAGNOSIS: Lower p3 large, double rooted, outline in occlusal view diamond shaped, with anterior portion of tooth rounded and posterior portion pointed. Lower p4 squarish to slightly rectangular in occlusal view, somewhat narrower anteriorly than posteriorly, with well-developed cingulum on anterior, labial, and posterior margins, but with cingular development weak to absent on the lingual margin. Lower m1 and m2 nyctalodont. Paraconid on m1 highly reduced, positioned labially about halfway between protoconid and metaconid. Metaconid on m1 and m2 taller than entoconid. Dentary with ascending ramus strongly upturned dorsally compared to horizontal ramus; angular process and articular condyle both located well dorsal to alveolar margin of toothrow; coronoid process with its anterior edge essentially vertical; articular condyle located well dorsal to tip of coronoid process; small secondary process present on ascending ramus immediately ventral to angular process. Upper P4 with large, rounded anterior basin, broad talon basin, and tall, sharp central cusp (protocone). Proximal humerus with head elliptical in shape, transversely flattened and directed proximally, and angled toward lesser trochanter. Distal humerus with articular surface moderately offset laterally from humeral shaπ; capitulum not differentiated into medial and lateral ridges; well-developed spinous process separated from medial edge of trochlea by deep notch; epitrochlea a well-developed rounded process with small concavity at proximomedial corner. Proximal end of radius gently rounded, not triangular. Proximal articular surface of radius with two articular facets. Femur with greater trochanter and lesser trochanter highly reduced; greater trochanter larger than lesser trochanter and triangular in shape. Distinct tubercle or short ridge present on posterodistal femoral shaft just proximal to distal articular surface. Femur comparatively long, more than three times longer than alveolar length of toothrow.

Pteronotus pristinus Pteronotus pristinus: Cuba: Las Villas, Cueva de Jaguey, near Trinidad (ROM 59132)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 138, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Pteronotus gymnonotus Pteronotus gymnonotus: Panama: Canal Zone, Barro Colorado Island, Allee Creek (USNM 498707); Canal Zone, Madden Dam, Chillibrillo Cave (AMNH 89998, USNM 306526, 306529– 30); Chilibre (USNM 305177); Colombia: Bolivar, Cartagena (USNM 431544); Peru: Huanuco, Parque Nacional de Tingo Maria (MSB 49905 – MSB 49906); Venezuela: Yaracui, Aroa; Bolivar R.R. (AMNH 32083–89, 32091–94)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 138, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Speonycteridae Speonycteris aurantiadens: United States, Florida, Hernando County, Brooksville 2 Locality, late Oligocene, early Arikareean NALMA (UF 240000 [holotype], mandible; 157759–61, isolated teeth; 157763–64, mandibles; 179952, isolated tooth; 179978, proximal femur; 182784, isolated tooth; 182797–99, isolated teeth; 182805, isolated tooth; 182849, isolated tooth); Florida, Alachua County, I-75 Locality, early Oligocene, Whitneyan NALMA (UF 16733, isolated tooth). Speonycteris naturalis: United States, Florida, Alachua County, I-75 Locality (UF 121717 [holotype], leπ M2)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 140, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Pteronotus davyi species group Pteronotus davyi davyi: Dominica: Grand Bay (USNM 361894); Roseau (AMNH 35923); Trinidad and Tobago: St. George, Arima Heights of Aripo (AMNH 29694); St. George, Diego Martin, Carenage (AMNH 29703–04); St. George, Port of Spain (AMNH 7445, 19122); Nariva (AMNH 207060); St. Patrick, Siparia (AMNH 179954). Pteronotus davyi incae: Peru: Cajamarca, Jaen (AMNH 69233); Piura, Huancabamba (AMNH 63721, 64082). Pteronotus fulvus: Mexico: Chiapas, 18 mi W Ixhuatan (AMNH 203563–64); Colima, Manzanillo, Playa de Oro (OMNH 26736); Colima, Cuauhtémoc, 0.5 mi E El Cobano (OMNH 14243); Jalisco, 7.5 km W Jamai, Cueva ‘‘ Deb’ ’ (204959–65); Jalisco, Los Masos (AMNH 27294– 96); Morelos, Cueva de Tequesquitengo (AMNH 204454–57, 204967–75); Sonora, 5 mi W Alamos (Mine Tunnel at La Aduana) (AMNH 180312); Sonora, La Aduana (MSB 53727); Ocozocoautla, Ocozocoautla (AMNH 171652); San Luis Potos, El Salto (AMNH 177588–611); Belize: Stann Creek (USNM 583006); El Salvador: La Union, Tabanco (AMNH 239229)., Published as part of Morgan, Gary S., Czaplewski, Nicholas J. & Simmons, Nancy B., 2019, A New Mormoopid Bat From The Oligocene (Whitneyan And Early Arikareean) Of Florida, And Phylogenetic Relationships Of The Major Clades Of Mormoopidae (Mammalia: Chiroptera), pp. 1-141 in Bulletin of the American Museum of Natural History 2019 (434) on page 138, DOI: 10.1206/0003-0090.434.1.1, http://zenodo.org/record/4613816

Velazco, Paúl M., Soto-Centeno, J. Angel, Fleck, David W., Voss, Robert S., Simmons, Nancy B. (2017): A New Species of Nectar-feeding Bat of the Genus Hsunycteris (Phyllostomidae: Lonchophyllinae) from Northeastern Peru. American Museum Novitates 2017 (3881): 1-28, DOI: 10.1206/3881.1, URL: http://www.bioone.org/doi/10.1206/3881.1

KEY TO THE SPECIES Of HSUNYCTERIS 1. Forearm ≥ 35.0 mm; hairs between the shoulders ≥ 9 mm; dermal papillae on chin arranged in a V and separated by a wide basal cleft; metacarpal V longer than metacarpal IV; rostrum broad; lateral margin of infraorbital foramen does not project beyond rostral outline in dorsal view; outer upper incisors large; P5 lingual cusp weakly developed.......................................................................... Hsunycteris dashe 1′. Forearm ≤ 34.5 mm; hairs between the shoulders ≤ 8 mm; dermal papillae on chin arranged in a V but not separated by a wide basal cleft; metacarpal V shorter than or subequal to metacarpal IV; rostrum narrow; lateral margin of infraorbital foramen does project beyond rostral outline in dorsal view; outer upper incisors small; P5 lingual cusp well-developed..............................................................2 2. Postorbital region with a lateral projection; M1 parastyle weakly developed; lower incisors large and broad; m1 paracristid notch strongly developed; m2 hypoconid wide...................................................................... Hsunycteris cadenai 2′. Postorbital region lacks a lateral projection; M1 parastyle well developed; lower incisors small and narrow; m1 paracristid notch weakly developed or absent; m2 hypoconid narrow....................................................................... 3 3. Metacarpal V shorter than metacarpal IV; extent of maxillary posterior to M3 less than the length of M3; dentary slender; angular process narrow; P4 lingual cusp absent; P5 lingual cusp narrow.................................................. Hsunycteris pattoni 3′. Metacarpal V subequal to metacarpal IV; extent of maxillary posterior to M3 greater than the length of M3; dentary deep; angular process broad; P4 lingual cusp present; P5 lingual cusp broad.................................................... Hsunycteris thomasi, Published as part of Velazco, Paúl M., Soto-Centeno, J. Angel, Fleck, David W., Voss, Robert S. & Simmons, Nancy B., 2017, A New Species of Nectar-feeding Bat of the Genus Hsunycteris (Phyllostomidae: Lonchophyllinae) from Northeastern Peru, pp. 1-28 in American Museum Novitates 2017 (3881) on pages 18-19, DOI: 10.1206/3881.1, http://zenodo.org/record/5369137

KEY TO THE SPECIES Of HSUNYCTERIS 1. Forearm ≥ 35.0 mm; hairs between the shoulders ≥ 9 mm; dermal papillae on chin arranged in a V and separated by a wide basal cleft; metacarpal V longer than metacarpal IV; rostrum broad; lateral margin of infraorbital foramen does not project beyond rostral outline in dorsal view; outer upper incisors large; P5 lingual cusp weakly developed.......................................................................... Hsunycteris dashe 1′. Forearm ≤ 34.5 mm; hairs between the shoulders ≤ 8 mm; dermal papillae on chin arranged in a V but not separated by a wide basal cleft; metacarpal V shorter than or subequal to metacarpal IV; rostrum narrow; lateral margin of infraorbital foramen does project beyond rostral outline in dorsal view; outer upper incisors small; P5 lingual cusp well-developed..............................................................2 2. Postorbital region with a lateral projection; M1 parastyle weakly developed; lower incisors large and broad; m1 paracristid notch strongly developed; m2 hypoconid wide...................................................................... Hsunycteris cadenai 2′. Postorbital region lacks a lateral projection; M1 parastyle well developed; lower incisors small and narrow; m1 paracristid notch weakly developed or absent; m2 hypoconid narrow....................................................................... 3 3. Metacarpal V shorter than metacarpal IV; extent of maxillary posterior to M3 less than the length of M3; dentary slender; angular process narrow; P4 lingual cusp absent; P5 lingual cusp narrow.................................................. Hsunycteris pattoni 3′. Metacarpal V subequal to metacarpal IV; extent of maxillary posterior to M3 greater than the length of M3; dentary deep; angular process broad; P4 lingual cusp present; P5 lingual cusp broad.................................................... Hsunycteris thomasi

Cf. Pipistrellus sp. REFERRED SPECIMENS: NMT.030/Bat, right distal humerus, FLK NNI, layer 2 or 3; NMT.040/ Bat, left distal humerus, FLK NI, layer 3, Tr. IV, 1964 (see table 1 for measurements). DESCRIPTION: Two fragmentary distal humeri from Olduvai represent pipistrelles, similar in size and morphology to Pipistrellus nanulus and P. rueppelli, the former known today from equatorial Africa and the latter from much of the African continent (Simmons, 2005). In anterior view the distal end of NMT.030/Bat has a narrow capitulum that is slightly angled and not offset from shaft. The lateral capitular tail is much less broad than the trochlear surface and is not separated from capitulum by a groove. The trochlear groove is moderately deep, the trochlear surface is relatively wide and robust, and the trochlear lip not sharply defined. The medial epicondylar process is small and extends distally only slightly beyond trochlear ridge. In posterior view, the groove on the lateral surface of the epicondyle is weak to absent. NMT.040/Bat differs slightly from NMT.030/Bat in lacking the slight angulation of the capitulum and in having a more sharply defined trochlear lip. Otherwise the two humeri are nearly identical. Pipistrelles are unknown from the fossil record in Africa outside Olduvai (Butler, 1978; Simmons and Gunnell, in prep.).

† Cardioderma leakeyi, new species Figures 4, 5 Megadermidae Butler and Greenwood, 1965: 14. Cardioderma sp., Butler, 1978: 65; Gunnell, 2010: 586. HOLOTYPE: NMT.003/Bat, left maxilla with P4–M3 (fig. 4), from the 1960 Olduvai Collection (see table 2 for measurements). REFERRED SPECIMEN: NMT.002/Bat, right dentary with m1–3, FLK NI, Layer 3. ETYMOLOGY: Named in honor of L.S.B. Leakey who was instrumental in initiating and leading the search for vertebrate fossils, especially fossil humans, in East Africa. TYPE LOCALITY: Tanzania: Olduvai Gorge, Bed I, FLK NI, Layer 2. DIAGNOSIS: Differs from extant Cardioderma cor in averaging 18%–20% larger in tooth dimensions; P4 with relatively larger parastyle and metastyle and better developed labial cingulum; M1–2 with relatively more robust mesostyle, deeper parafossa and metafossa, and deeper trigon basin; less reduced M3/m3; m1 and m2 with relatively broader talonid basin and more robust metaconid; m3 with broader trigonid and less reduced talonid. DESCRIPTION AND COMPARISONS: The specimens referred to Cardioderma leakeyi can be recognized as megadermatids based on the robust nature of the cusps and crests on upper and lower cheek teeth, the large hypocone shelves and the narrow and labiolingually restricted protofossae on M1–2, the broadly open trigonid on m1 and the high and short lower molar talonids. The holotype maxilla (NMT.003/Bat, fig. 4) has a maxillary foramen that opens over the anterior root of P4 as in the extant species of Cardioderma, C. cor. There is a secondary and smaller foramen that opens more ventrally on the maxilla over the posterior root of P4 (this foramen is slightly more posteriorly placed in the extant species). In lateral view, the anterior labial root of M1 is exposed through the bony surface of the maxilla, as is often the case in C. cor. The root of the zygomatic arch is dorsal to M2 as in the living form, but it is much more robust in C. leakeyi, as is the anterior orbital process. The optical foramen is the same size and in the same position in both species of Cardioderma. The P4 of Cardioderma leakeyi has a robust paracone, relatively large parastyle and metastyle, and a relatively heavy labial cingulum. The lingual cingulum is relatively broad anteroposteriorly and extends lingually farther than is seen in C. cor. M1–2 each have a prominent hypocone shelf, an anteroposteriorly narrow but labiolingually extended and deep protofossa, a robust mesostyle, and parastylar and metastylar foveae that are nearly equivalent in size (whereas in C. cor the metastylar fovea is typically larger). M3 has a relatively robust parastyle and a labiolingually short lingual shelf and is less anteroposteriorly compressed than seen in C. cor. The horizontal ramus of the dentary (NMT.002/Bat) is relatively deep in Cardioderma leakeyi (3.0 mm beneath m1) compared to C. cor (2.0 mm below m1). The lower molars of C. leakeyi (fig. 5) are all quite similar to those of extant C. cor. The m1 is broken anteriorly, making it impossible to tell whether C. leakeyi had a small, low, and centered paraconid as seen in C. cor. All three lower molars of C. leakeyi have a prominent protoconid and a somewhat lower, but distinct, metaconid. Lower m2 and m3 have distinct paraconids that are placed somewhat lower than the metaconids. The hypoflexid is deep and the cristid obliqua is angled and joins the postvallid of the trigonid well lingual of center on all molar teeth. The hypoconid on m1–2 is distinct, but it is less so on m3; the entoconid is distinct only on m1. Molar talonids are broader than those seen in C. cor, but the talonid is not as broad as the trigonid on any tooth. All molars have moderate and complete labial cingulids. The only other published record of a fossil Cardioderma species (Louchart et al., 2009) is from the early Pliocene in Ethiopia. However, the material upon which that assignment is based has never been described or figured making comparisons impossible at this time., Published as part of Gunnell, Gregg F., Butler, Percy M., Greenwood, Marjorie & Simmons, Nancy B., 2015, Bats (Chiroptera) from Olduvai Gorge, Early Pleistocene, Bed I (Tanzania), pp. 1-35 in American Museum Novitates 2015 (3846) on pages 7-10, DOI: 10.1206/3846.1, http://zenodo.org/record/4598312, {"references":["Butler, P. M., and M. Greenwood 1965. Chiroptera. In L. S. B. Leakey (editor), Olduvai Gorge 1951 - 1961, vol. 1. A preliminary report on the geology and fauna: 14 - 15. Cambridge: Cambridge University Press.","Butler, P. M. 1978. Insectivora and Chiroptera. In V. J. Maglio and H. B. S. Cooke (editors), Evolution of African mammals: 56 - 68. Cambridge, MA: Harvard University Press.","Gunnell, G. F. 2010. Chiroptera. In L. Werdelin and W. J. Sanders (editors), Cenozoic Mammals of Africa: 581 - 597. Berkeley: University of California Press.","Louchart, A., et al. 2009. Taphonomic, avian, and small-vertebrate indicators of Ardipithecus ramidus habitat. Science 326: 66. [doi 10.1126 / science. 1175823]"]}

† Myzopoda africana, new species Figures 2, 3 Myzopoda sp., Butler, 1978: 65; Gunnell, 2010: 586. HOLOTYPE: NMT.010/Bat, complete left humerus (see table 1 for measurements). ETYMOLOGY: The species name is given for the African continent, since the new species represents the only known occurrence of the genus Myzopoda on continental Africa; extant species are restricted to Madagascar. TYPE LOCALITY: Tanzania: Arusha Province, Olduvai Gorge, Bed I, FLK NI, Layer 123. DIAGNOSIS: Differs from living Myzopoda schliemanni and M. aurita in having a larger humerus (mean dimensions 21% larger) that is more robust and has a relatively longer deltopectoral crest, a more rounded humeral head, a more robust lesser tubercle, a more distinct and elongate lateral capitular tail, a more distinct and laterally compressed capitulum, and a relatively broader epitrochlea with a more distally extended epitrochlear process. REFERRED SPECIMENS: NMT.008/Bat, left proximal humerus from Olduvai Bed I, FLK NI, layer 123; NMT.009/Bat, right distal humerus, Olduvai Bed 1, FLK NI, layer 4 (collected 1960). DESCRIPTION: Three humeri from Olduvai can be assigned to Myzopoda based on the presence of the following combination of characters: round, bulbous capitulum, extended capitular tail with flaring lip, a broad epicondyle with two distinct processes, and a humeral head placed distal to the trochiter (greater tubercle). The proximal humerus (fig. 2) of M. africana has a semi-rounded, distolaterally slightly flattened head. The proximal extent of the head does not extend as far proximally as the trochiter and is even slightly below the proximal extent of the lesser tubercle. The deltopectoral crest is elevated anteriorly, is relatively long and curving, and has a sharply defined anterior margin with a slight overhanging lip developed medially. Distally (figs. 2, 3), the humerus of M. africana has a rounded and slightly laterally compressed capitulum that is robust and not offset from the long axis of the humeral shaft. The lateral capitular tail is as broad as the trochlear surface. The trochlear groove is distinct but not deeply invaginated and with a sharply defined trochlear lip. The medial epicondyle is robust with a relatively elongate process that extends distally beyond the trochlear ridge and is developed as two rounded surfaces aligned anteroposteriorly. There is a small but distinct groove on the lateral surface of the epicondyle. Other fossil material of Myzopoda is unknown from both Africa and Madagascar, although more ancient myzopodids referred to another genus have been described from Egypt (Gunnell et al., 2014)., Published as part of Gunnell, Gregg F., Butler, Percy M., Greenwood, Marjorie & Simmons, Nancy B., 2015, Bats (Chiroptera) from Olduvai Gorge, Early Pleistocene, Bed I (Tanzania), pp. 1-35 in American Museum Novitates 2015 (3846) on pages 3-7, DOI: 10.1206/3846.1, http://zenodo.org/record/4598312, {"references":["Butler, P. M. 1978. Insectivora and Chiroptera. In V. J. Maglio and H. B. S. Cooke (editors), Evolution of African mammals: 56 - 68. Cambridge, MA: Harvard University Press.","Gunnell, G. F. 2010. Chiroptera. In L. Werdelin and W. J. Sanders (editors), Cenozoic Mammals of Africa: 581 - 597. Berkeley: University of California Press.","Gunnell, G. F., N. B. Simmons, and E. R. Seiffert. 2014. New Myzopodidae (Chiroptera) from the late Paleogene of Egypt: emended family diagnosis and biogeographic origins of Noctilionoidea. PLoS ONE 9 (2): e 86712. [doi: 10.1371 / journal. pone. 0086712]"]}

Cf. Eptesicus isabellinus Figure 8 Eptesicus cf. hottentotus, Butler, 1978: 65. REFERRED SPECIMEN: NMT.032/Bat, right distal humerus, FLK NI, layer 6, 1964 (see table 1 for measurements). DESCRIPTION AND DISCUSSION: Olduvai specimen NMT.032/Bat represents a vespertilionid humerus very similar in size and morphology to that of extant Eptesicus isabellinus. NMT.032/Bat (fig. 8, bottom row) has a narrow but robust capitulum that is not angled or offset from shaft. The lateral capitular tail is much less broad than the trochlear surface, and is separated from the capitulum by a shallow groove. A trochlear groove is absent and the trochlear surface is relatively wide and robust with a sharply defined trochlear lip. The medial epicondylar process is low and robust and does not extend distally beyond the trochlear ridge. Groove on the lateral surface of epicondyle is weak to absent. These are all features typical of Eptesicus. The taxonomy of Eptesicus isabellinus is unresolved at the moment, but it appears to be the North African representative of the Eptesicus serotinus radiation sensu lato (Simmons, 2005). However, it is not clear whether E. isabellinus can be maintained as a species separate from E. serotinus (Simmons, 2005). We have chosen to retain it as distinct subject to revision of circumMediterranean Eptesicus species. NMT.032/Bat very closely resembles E. isabellinus (NHMUK 19.7.7.1160, fig. 8, top row) in nearly every detail of size and morphology. The fossil specimen has a slightly less distally extended epicondylar process and the distal end is slightly deeper anteroposteriorly. NMT.032 differs from Eptesicus furinalis (AMNH 278332) only in being relatively larger with a slightly broader capitulum and lacking any groove between the capitulum and trochlea. The lateral ridge is slightly broader than in the extant taxon but otherwise similar. The only records of Eptesicus fossil material from Africa all come from southern Africa (Hendey, 1981; Pocock, 1987; Avery, 1998), mostly from the early to late Pliocene deposits, and they are based on teeth and jaws that are not directly comparable to the specimen described here. Eptesicus is a common element of other Plio-Pleistocene faunal communities and is widespread across the northern continents during this time period (Simmons and Gunnell, in prep.)., Published as part of Gunnell, Gregg F., Butler, Percy M., Greenwood, Marjorie & Simmons, Nancy B., 2015, Bats (Chiroptera) from Olduvai Gorge, Early Pleistocene, Bed I (Tanzania), pp. 1-35 in American Museum Novitates 2015 (3846) on pages 13-15, DOI: 10.1206/3846.1, http://zenodo.org/record/4598312, {"references":["Butler, P. M. 1978. Insectivora and Chiroptera. In V. J. Maglio and H. B. S. Cooke (editors), Evolution of African mammals: 56 - 68. Cambridge, MA: Harvard University Press.","Simmons, N. B. 2005. Order Chiroptera. In D. E. Wilson and D. M. Reeder (editors), Mammal species of the world, a taxonomic and geographic reference, vol. 1: 312 - 529. Baltimore: Johns Hopkins University Press.","Hendey, Q. B. 1981. Paleoecology of the late Tertiary fossil occurrences in \" E \" Quarry, Langebaanweg, South Africa, and a reinterpretation of their geological context. Annals of the South African Museum 84: 1 - 104.","Pocock, T. N. 1987. Plio-Pleistocene fossil mammalian microfauna of southern Africa - a preliminary report including description of two new fossil Muroid genera (Mammalia: Rodentia). Palaeontologia Africana 26: 69 - 91.","Avery, D. M. 1998. An assessment of the Lower Pleistocene micromammalian fauna from Swartkrans members 1 - 3, Gauteng, South Africa. Geobios 31: 393 - 414."]}

† Cardioderma leakeyi, new species Figures 4, 5 Megadermidae Butler and Greenwood, 1965: 14. Cardioderma sp., Butler, 1978: 65; Gunnell, 2010: 586. HOLOTYPE: NMT.003/Bat, left maxilla with P4–M3 (fig. 4), from the 1960 Olduvai Collection (see table 2 for measurements). REFERRED SPECIMEN: NMT.002/Bat, right dentary with m1–3, FLK NI, Layer 3. ETYMOLOGY: Named in honor of L.S.B. Leakey who was instrumental in initiating and leading the search for vertebrate fossils, especially fossil humans, in East Africa. TYPE LOCALITY: Tanzania: Olduvai Gorge, Bed I, FLK NI, Layer 2. DIAGNOSIS: Differs from extant Cardioderma cor in averaging 18%–20% larger in tooth dimensions; P4 with relatively larger parastyle and metastyle and better developed labial cingulum; M1–2 with relatively more robust mesostyle, deeper parafossa and metafossa, and deeper trigon basin; less reduced M3/m3; m1 and m2 with relatively broader talonid basin and more robust metaconid; m3 with broader trigonid and less reduced talonid. DESCRIPTION AND COMPARISONS: The specimens referred to Cardioderma leakeyi can be recognized as megadermatids based on the robust nature of the cusps and crests on upper and lower cheek teeth, the large hypocone shelves and the narrow and labiolingually restricted protofossae on M1–2, the broadly open trigonid on m1 and the high and short lower molar talonids. The holotype maxilla (NMT.003/Bat, fig. 4) has a maxillary foramen that opens over the anterior root of P4 as in the extant species of Cardioderma, C. cor. There is a secondary and smaller foramen that opens more ventrally on the maxilla over the posterior root of P4 (this foramen is slightly more posteriorly placed in the extant species). In lateral view, the anterior labial root of M1 is exposed through the bony surface of the maxilla, as is often the case in C. cor. The root of the zygomatic arch is dorsal to M2 as in the living form, but it is much more robust in C. leakeyi, as is the anterior orbital process. The optical foramen is the same size and in the same position in both species of Cardioderma. The P4 of Cardioderma leakeyi has a robust paracone, relatively large parastyle and metastyle, and a relatively heavy labial cingulum. The lingual cingulum is relatively broad anteroposteriorly and extends lingually farther than is seen in C. cor. M1–2 each have a prominent hypocone shelf, an anteroposteriorly narrow but labiolingually extended and deep protofossa, a robust mesostyle, and parastylar and metastylar foveae that are nearly equivalent in size (whereas in C. cor the metastylar fovea is typically larger). M3 has a relatively robust parastyle and a labiolingually short lingual shelf and is less anteroposteriorly compressed than seen in C. cor. The horizontal ramus of the dentary (NMT.002/Bat) is relatively deep in Cardioderma leakeyi (3.0 mm beneath m1) compared to C. cor (2.0 mm below m1). The lower molars of C. leakeyi (fig. 5) are all quite similar to those of extant C. cor. The m1 is broken anteriorly, making it impossible to tell whether C. leakeyi had a small, low, and centered paraconid as seen in C. cor. All three lower molars of C. leakeyi have a prominent protoconid and a somewhat lower, but distinct, metaconid. Lower m2 and m3 have distinct paraconids that are placed somewhat lower than the metaconids. The hypoflexid is deep and the cristid obliqua is angled and joins the postvallid of the trigonid well lingual of center on all molar teeth. The hypoconid on m1–2 is distinct, but it is less so on m3; the entoconid is distinct only on m1. Molar talonids are broader than those seen in C. cor, but the talonid is not as broad as the trigonid on any tooth. All molars have moderate and complete labial cingulids. The only other published record of a fossil Cardioderma species (Louchart et al., 2009) is from the early Pliocene in Ethiopia. However, the material upon which that assignment is based has never been described or figured making comparisons impossible at this time.

Miniopterus cf. M. schreibersi (Kuhl, 1817) Figures 14, 15 Miniopterus cf. schreibersi, Butler, 1978: 65; Gunnell, 2010: 588. REFERRED SPECIMENS: NMT.007/Bat, right dentary p3–4 (p4 now lost but shown in drawings of MG), from FLK NI, layer 5, Tr. IV; NMT.011/Bat, left and right distal humeri, from FLK NI, layer 3; NMT.017/Bat, right distal humerus, from FLK NI, layer 2; NMT.019/Bat, right proximal humerus, FLK NI, layer 2 (maybe not Miniopterus, poorly preserved); NMT.022/Bat, left proximal humerus, right distal humeri (2), humeral shaft, from FLK, Main Dig Z level; NMT.038/Bat, right distal humerus, from FLK NI, layer 3, Tr. IV (see tables 1 and 2 for measurements). DESCRIPTION AND DISCUSSION: One dental specimen representing Miniopterus cf. M. schreibersi is known from the Olduvai sample, a right dentary (NMT.007/Bat) that originally had p3–4 and the alveoli for all other teeth preserved. The p3 is double rooted with a single, lingually placed cusp that has a sloping, convex buccal surface and straight, flat lingual surface. A continuous, weakly developed cingulid is present that is developed into a tiny posterolingual extension. In detailed morphology this p3 is quite similar to that of extant M. schreibersi (fig. 14). The p4 was originally in place in this specimen and based on the available drawings (see fig. 14) it was very similar to p4 of extant M. schreibersi. It shared the presence of a tall, pointed protoconid and a broad but short talonid shelf formed by the distal cingulid with the extant taxon. Both extinct and extant specimens lack any indication of a para- or metaconid and both have well-developed labial and lingual cingulids that join anteriorly with the labial cingulid sloping ventrally from anterior to posterior. The dentary has a large mental foramen beneath the c1–p2 roots. Based on alveoli, p2 was single rooted as in living M. schreibersi. The i3 alveolus is slightly separated from the conjoined i1–2 alveoli and is larger than either of the other incisor alveoli as in extant Miniopterus species, and all incisor alveoli are aligned mesiodistally. There is a smaller mental foramen below the i1 alveolus on anterior surface of dentary. The humeral fragments of the Olduvai Miniopterus specimens are very similar in size and morphology to the humerus of extant Miniopterus schreibersi. The proximal end of the humerus in Olduvai Miniopterus specimens has a moderately high (anteriorly) deltopectoral crest that is relatively long and sharply defined. It has a distinct, overhanging medial lip. The crest curves to the base of the trochiter and anteriorly encloses a relatively deep intertrochanteric fossa. The head of the humerus is ovate and angled. The proximal margin of the head does not extend as far proximally as the trochiter, instead extending proximally about the same distance as the lesser trochanter. The distal end of the Miniopterus humerus has a narrow, rounded capitulum that is slightly angled and is not offset from shaft. The lateral capitular tail is somewhat broader than the trochlear surface and is separated from the capitulum by a deep and distinct groove. In contrast, the trochlear groove is faint and the trochlear surface is relatively narrow with a sharply defined trochlear lip. The medial epicondylar process is broken in all Olduvai specimens, but, judging by what remains, it would have been distinct and would have extended well beyond the trochlear ridge as it does in extant Miniopterus (fig. 15). The groove on the lateral surface of the epicondyle is absent, but there is a distinct fossa that occurs on the lateral surface below the root of the epicondylar process. Like all other Miniopterus species, the specimens from Olduvai have well developed and deep olecranon fossae (see fig. 15B, top and bottom), a feature not commonly found in bats. These Olduvai specimens are assigned to Miniopterus cf. M. schreibersi because they are very similar in morphological detail to the humerus of the living taxon. However, Miniopterus schreibersi is not the only similar-sized Miniopterus species to occupy sub-Saharan Africa today. Therefore it is possible that the Olduvai species might be more closely related to one of the other species, especially M. africanus or M. inflatus, given that both of these species have been confused with M. schreibersi in the past (Simmons, 2005). We have chosen to follow Butler’s (1978) original assignment of these specimens to Miniopterus cf. M. schreibersi but acknowledge that more complete specimens are needed to assess the precise relationship of the Olduvai Miniopterus species to living members of that genus. The African fossil record of Miniopterus is limited to the record from Olduvai, two Pliocene records from South Africa (Pocock, 1987) and a late Pliocene record from Morocco (Gunnell et al., 2011). The South African Pliocene occurrences are recorded in faunal lists, but the specimens upon which the assignments are based have never been described or figured., Published as part of Gunnell, Gregg F., Butler, Percy M., Greenwood, Marjorie & Simmons, Nancy B., 2015, Bats (Chiroptera) from Olduvai Gorge, Early Pleistocene, Bed I (Tanzania), pp. 1-35 in American Museum Novitates 2015 (3846) on pages 23-28, DOI: 10.1206/3846.1, http://zenodo.org/record/4598312, {"references":["Kuhl, H. 1817. Die deutschen Fledermause. Hanau 22: 1 - 67.","Butler, P. M. 1978. Insectivora and Chiroptera. In V. J. Maglio and H. B. S. Cooke (editors), Evolution of African mammals: 56 - 68. Cambridge, MA: Harvard University Press.","Gunnell, G. F. 2010. Chiroptera. In L. Werdelin and W. J. Sanders (editors), Cenozoic Mammals of Africa: 581 - 597. Berkeley: University of California Press.","Simmons, N. B. 2005. Order Chiroptera. In D. E. Wilson and D. M. Reeder (editors), Mammal species of the world, a taxonomic and geographic reference, vol. 1: 312 - 529. Baltimore: Johns Hopkins University Press.","Vaughan, T. A. 1976. Nocturnal behavior of the African false vampire bat (Cardioderma cor). Journal of Mammalogy 51: 227 - 248.","Csada, R. 1996. Cardioderma cor. Mammalian Species 519: 1 - 4.","Rosevear, D. R. 1965. The bats of West Africa. London: British Museum (Natural History).","Smithers, R. H. N. 1983. The mammals of the southern African subregion. Pretoria: University of Pretoria.","Johnston, D. S. 2006. Nycticeinops schlieffeni. Mammalian Species 798: 104.","Kingdon, J. 1974. East African mammals: an atlas of evolution in Africa. II (A). Insectivores and bats. London: Academic Press.","Hill, J E. 1974. A review of Scotoecus Thomas, 1901 (Chiroptera: Vespertilionidae). Bulletin of the British Museum (Natural History), Zoology 27: 169 - 188.","Jacobs, D. 2008. Scotoecus albofuscus. The IUCN red list of threatened species. Version 2015.2.","Van der Merwe, M. 1975. Preliminary study on the annual movements of the Natal clinging bats. South African Journal of Science 71: 237 - 241.","Nowak R. M. 1994. Walker's bats of the world. Baltimore: Johns Hopkins University Press.","Taylor, P. 1998. The smaller mammals of KwaZulu-Natal. Pietermaritzburg, South Africa: University of Natal Press.","Mickleburgh, S., A. M. Hutson, W. Bergmans, and J. Fahr. 2008 b. Nycteris thebaica. The IUCN red list of threatened species. Version 2015.2.","Happold, D. C. D. 1987. The mammals of Nigeria. London: Oxford University Press.","Hayman, R. W. 1954. Notes on some African Bats, mainly from the Belgian Congo. Revue de Zoologie et de Botanique Africaines 50: 277 - 295.","Goodman, S. M., et al. 2005. The distribution and conservation of bats in the dry regions of Madagascar. Animal Conservation 8: 153 - 165.","MacKinnon, J., C. E. Hawkins, and P. A. Racey. 2003. Pteropodidae. In S. M. Goodman and J. P. Benstead (editors), The natural history of Madagascar: 1299 - 1302. Chicago: University of Chicago Press.","Mickleburgh, S., A. M. Hutson, W. Bergmans, J. Fahr, and P. A. Racey. 2008 c. Eidolon helvum. The IUCN red list of threatened species. Version 2015.2.","Mickleburgh, S., A. M. Hutson, W. Bergmans, F. W. Cotterill, J. Fahr, and D. Jacobs. 2008 a. Tadarida aegyptiaca. The IUCN red list of threatened species. Version 2015.2.","Olsson, A., D. Emmett, D. Henson, and E. Fanning, E. 2006. Abundance and activity patterns of microchiropteran bats at a cave roost in southwest Madagascar. African Journal of Ecology 44: 401 - 403.","Pocock, T. N. 1987. Plio-Pleistocene fossil mammalian microfauna of southern Africa - a preliminary report including description of two new fossil Muroid genera (Mammalia: Rodentia). Palaeontologia Africana 26: 69 - 91.","Gunnell, G. F., T. P. Eiting, and D. Geraads. 2011. New late Pliocene bats (Chiroptera) from Ahl al Oughlam, Morocco. Neues Jahrbuch fur Geologie und Palaontologie 260: 55 - 71."]}

† Nycticeinops serengetiensis, new species Figures 9, 10 Cf. Nycticeius (Scoteinus) schlieffeni, Butler and Greenwood, 1965: 15; Butler, 1978: 65; Gunnell, 2010: 588. HOLOTYPE: NMT.005/Bat, right dentary with p4–m1 and alveoli for all other teeth (fig. 9F–H; see table 2 for measurements). REFERRED SPECIMENS: NMT.001/Bat, left dentary with m2–3 and alveoli for all anterior teeth, from FLK NI, layer 123; NMT.006/Bat, left edentulous dentary preserving all tooth alveoli, from FLK NI, layer 1; NMT.013/Bat, left distal humerus, from FLK NI, layer 2; NMT.015/Bat, right distal humeri (3), from FLK NI, layer 123; NMT.016/Bat, left and right distal humeri, from FLK NI, layer 3; NMT.023/Bat, right distal humerus (and most of shaft), from Main Dig, FLK 1, Z level; NMT.025/Bat, left distal humerus, from FLK1, Z level; NMT.034/Bat, left proximal humerus, from FLK NI, layer 1, Tr. IV, 1964; NMT.035/Bat, right distal humeri (2), from FLK NI, layer 5, Tr. IV, 1964; NMT.036/Bat, left distal humerus, from FLK NI, layer 2, Tr. V; NMT.037/Bat, left and right distal humeri, from FLK NI, layer 1, Tr. III (see table 1 for measurements). ETYMOLOGY: Named for the famed Serengeti region in northern Tanzania where Olduvai Gorge is located. TYPE LOCALITY: Tanzania: Olduvai Gorge, Bed I, FLK NI, layer 5, Tr. IV. DIAGNOSIS: Differs from extant Nycticeinops schlieffeni (the only other recognized species of the genus) in having teeth on average 20% larger; p4 relatively taller and labiolingually narrower with a relatively longer talonid shelf; m1 with more curved paracristid and more angled entocristid, hypoconulid relatively lower and talonid basin more deeply excavated; m2 with relatively lower hypoconulid; and m3 with heavier anterolabial cingulid. DESCRIPTION AND DISCUSSION: All three of the known fossil jaws have slightly different arrangements of their incisor alveoli. The holotype of N. serengetiensis (NMT.005/Bat) has a small i3 alveolus directly in front of the canine alveolus while a slightly larger i2 alveolus is anteromedial to that of i3 and directly posterior to an equally large i1 alveolus. NMT.001/Bat has a similar arrangement except that the i1 alveolus is noticeably larger than either the i2 or i3 alveoli and is placed somewhat more laterally, producing a triangular arrangement of alveoli. The edentulous dentary of N. serengetiensis (NMT.006/Bat) is more similar to the holotype except that the alveoli of i2 and i3 are nearly mediolaterally opposite one another and the i2 alveolus is smaller. The arrangement of incisors in extant Nycticeinops schlieffeni (e.g., AMNH 257406) is somewhat different in that the i2 alveolus is not as far medial but instead forms part of a non-arcuate row of incisors running from the canine to the midline of the jaw with i1 most anterior and i3 most posterior. The offset arrangement found in N. serengetiensis may, in part, be due to the larger teeth of the fossil form and subsequent crowding of teeth in the jaw (although certain other extant vespertilionids also have a similar arrangement of incisor alveoli to those seen in N. serengetiensis; N.J. Czaplewski, personal commun.). As further evidence of this crowding, the p4 of NMT.005/Bat is very closely appressed to the m1 with the m1 overlapping the p4 talonid shelf. The dentaries of N. serengetiensis are all broken posteriorly but preserve enough of the ascending ramus to show that it rose dorsally at a shallower angle than that in N. schlieffeni, in which the ramus rises more steeply and then turns anteriorly (fig. 9A). Like in the extant taxon, there is typically a single mental foramen located beneath the area of contact between c1–p3, but it is relatively larger in N. serengetiensis, which occasionally has a smaller foramen located more anteriorly as well (fig. 9D). The dentaries of N. serengetiensis also differ from the modern species by having their ventral borders gently sloping dorsally from posterior to anterior and then ending anteriorly by turning dorsally. In N. schlieffeni the dorsal border of the dentary angles dorsally from posterior to anterior and forms a continuous surface with no angulation producing a jaw that is deeper beneath p4 than it is beneath m3. The Olduvai collection includes 13 distal humeri and one proximal humerus that we refer to N. serengetiensis based on their similarity to those of extant N. schlieffeni. NMT.034/Bat is a left proximal humerus that has a semi-rounded and slightly angled head that does not extend quite as far proximally as the trochiter but does extend slightly past the lesser trochanter. The deltopectoral crest is high anteriorly and fairly long, and has a sharply defined edge with a slightly overhanging lip developed medially. The crest curves toward the base of the trochiter and anteriorly encloses a moderately deep intertrochanteric fossa. The distal humerus of N. serengetiensis is characterized by a relatively narrow capitulum that is neither angled nor offset from the shaft. The lateral capitular tail is much less broad than the trochlear surface and is separated from the capitulum by a very shallow groove. The trochlear groove is weak and the trochlear lip is sharply defined. The medial epicondyle has a small process that extends distally only slightly beyond trochlear ridge. The groove on lateral surface of epicondyle is moderately developed. Other than the specimens described here no other fossils of Nycticeinops are known (Simmons and Gunnell, in prep.)., Published as part of Gunnell, Gregg F., Butler, Percy M., Greenwood, Marjorie & Simmons, Nancy B., 2015, Bats (Chiroptera) from Olduvai Gorge, Early Pleistocene, Bed I (Tanzania), pp. 1-35 in American Museum Novitates 2015 (3846) on pages 17-19, DOI: 10.1206/3846.1, http://zenodo.org/record/4598312, {"references":["Butler, P. M., and M. Greenwood 1965. Chiroptera. In L. S. B. Leakey (editor), Olduvai Gorge 1951 - 1961, vol. 1. A preliminary report on the geology and fauna: 14 - 15. Cambridge: Cambridge University Press.","Butler, P. M. 1978. Insectivora and Chiroptera. In V. J. Maglio and H. B. S. Cooke (editors), Evolution of African mammals: 56 - 68. Cambridge, MA: Harvard University Press.","Gunnell, G. F. 2010. Chiroptera. In L. Werdelin and W. J. Sanders (editors), Cenozoic Mammals of Africa: 581 - 597. Berkeley: University of California Press."]}

† Myzopoda africana, new species Figures 2, 3 Myzopoda sp., Butler, 1978: 65; Gunnell, 2010: 586. HOLOTYPE: NMT.010/Bat, complete left humerus (see table 1 for measurements). ETYMOLOGY: The species name is given for the African continent, since the new species represents the only known occurrence of the genus Myzopoda on continental Africa; extant species are restricted to Madagascar. TYPE LOCALITY: Tanzania: Arusha Province, Olduvai Gorge, Bed I, FLK NI, Layer 123. DIAGNOSIS: Differs from living Myzopoda schliemanni and M. aurita in having a larger humerus (mean dimensions 21% larger) that is more robust and has a relatively longer deltopectoral crest, a more rounded humeral head, a more robust lesser tubercle, a more distinct and elongate lateral capitular tail, a more distinct and laterally compressed capitulum, and a relatively broader epitrochlea with a more distally extended epitrochlear process. REFERRED SPECIMENS: NMT.008/Bat, left proximal humerus from Olduvai Bed I, FLK NI, layer 123; NMT.009/Bat, right distal humerus, Olduvai Bed 1, FLK NI, layer 4 (collected 1960). DESCRIPTION: Three humeri from Olduvai can be assigned to Myzopoda based on the presence of the following combination of characters: round, bulbous capitulum, extended capitular tail with flaring lip, a broad epicondyle with two distinct processes, and a humeral head placed distal to the trochiter (greater tubercle). The proximal humerus (fig. 2) of M. africana has a semi-rounded, distolaterally slightly flattened head. The proximal extent of the head does not extend as far proximally as the trochiter and is even slightly below the proximal extent of the lesser tubercle. The deltopectoral crest is elevated anteriorly, is relatively long and curving, and has a sharply defined anterior margin with a slight overhanging lip developed medially. Distally (figs. 2, 3), the humerus of M. africana has a rounded and slightly laterally compressed capitulum that is robust and not offset from the long axis of the humeral shaft. The lateral capitular tail is as broad as the trochlear surface. The trochlear groove is distinct but not deeply invaginated and with a sharply defined trochlear lip. The medial epicondyle is robust with a relatively elongate process that extends distally beyond the trochlear ridge and is developed as two rounded surfaces aligned anteroposteriorly. There is a small but distinct groove on the lateral surface of the epicondyle. Other fossil material of Myzopoda is unknown from both Africa and Madagascar, although more ancient myzopodids referred to another genus have been described from Egypt (Gunnell et al., 2014).

Cf. Myotis sp. Myotis sp., Butler, 1978: 65; Gunnell, 2010: 588. REFERRED SPECIMEN: NMT.012/Bat, left damaged distal humerus, FLK NI, layer 3 (see table 1 for measurements). DESCRIPTION AND DISCUSSION: NMT.012/Bat is the only specimen in the Olduvai sample that may represent Myotis. The distal end of the humerus of NMT.012/Bat has typical Myotis features including having a relatively narrow capitulum that is not offset from shaft, a lateral capitular tail that is less broad than trochlear surface and proximolaterally extended into a distinct lip, a trochlear groove that is essentially absent, and a trochlear surface that is relatively broad with a trochlear lip that is not sharply defined. Additionally, the medial epicondyle has a small process that does not extend distally beyond the trochlear ridge and the groove on the posterolateral surface of the epicondyle is deep, narrow, and distinct. Of the 12 Myotis species living in Africa today (Simmons, 2005), only M. dieteri (Democratic Republic of Congo), M. morrisi (Ethiopia, Nigeria), M. scotti (Ethiopia), M. tricolor (subSaharan Africa), M. bocagii (western and southern Africa), and M. welwitschii (sub-Saharan Africa) are found south of the Sahara, and of these only M. welwitschii lives in Tanzania today. NMT.012/Bat represents a relatively large species of Myotis, such as M. welwitschii, and may well be related to, or even represent, that species. Myotis is poorly represented in the fossil record of Africa in the Plio-Pleistocene and is restricted to southern Africa (Broom, 1948; Pocock, 1987) outside of the record from Tanzania and an occurrence in Morocco (Gunnell et al., 2011). Myotis is a common element of other Plio-Pleistocene faunal communities and is widespread across the northern continents during this time period (Simmons and Gunnell, in prep.)., Published as part of Gunnell, Gregg F., Butler, Percy M., Greenwood, Marjorie & Simmons, Nancy B., 2015, Bats (Chiroptera) from Olduvai Gorge, Early Pleistocene, Bed I (Tanzania), pp. 1-35 in American Museum Novitates 2015 (3846) on page 15, DOI: 10.1206/3846.1, http://zenodo.org/record/4598312, {"references":["Butler, P. M. 1978. Insectivora and Chiroptera. In V. J. Maglio and H. B. S. Cooke (editors), Evolution of African mammals: 56 - 68. Cambridge, MA: Harvard University Press.","Gunnell, G. F. 2010. Chiroptera. In L. Werdelin and W. J. Sanders (editors), Cenozoic Mammals of Africa: 581 - 597. Berkeley: University of California Press.","Simmons, N. B. 2005. Order Chiroptera. In D. E. Wilson and D. M. Reeder (editors), Mammal species of the world, a taxonomic and geographic reference, vol. 1: 312 - 529. Baltimore: Johns Hopkins University Press.","Broom, R. 1948. Some South African Pliocene and Pleistocene mammals. Annals of the Transvaal Museum 21: 1 - 38.","Pocock, T. N. 1987. Plio-Pleistocene fossil mammalian microfauna of southern Africa - a preliminary report including description of two new fossil Muroid genera (Mammalia: Rodentia). Palaeontologia Africana 26: 69 - 91.","Gunnell, G. F., T. P. Eiting, and D. Geraads. 2011. New late Pliocene bats (Chiroptera) from Ahl al Oughlam, Morocco. Neues Jahrbuch fur Geologie und Palaontologie 260: 55 - 71."]}