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After about a century, the skull of the holotype and sole specimen of Arambourgia gaudryi from the Eocene of Quercy (France) is here redescribed. Its interest resides in its extreme morphology, such as its very small skull and altirostral condition, that raises questions about its maturity, taxonomic validity, and paleoecology. In order to reveal previously hidden anatomical details, we used computed microtomography (µCT-scan) data to digitally extract the bones of the cranium and mandible, as well as the endocranial structures. Here, we update the osteological description of A. gaudryi, outlining new characters and re-evaluating anatomical details. Comparing it with ontogenetic series of extant crocodylians, we confirm that the specimen is a mature individual of a dwarf species with pedomorphic features. Our phylogenetic analyses indicate that A. gaudryi is an alligatorine. Comparisons with other small alligatoroid taxa show that it is indeed a valid species. The depositional environment of the finding site suggests a continental context with a karstic network. Taking this into account, together with its peculiar anatomy, we propose that A. gaudryi was a semi-terrestrial animal occupying an ecological niche similar to that of extant juvenile or dwarf crocodylians. Finally, we discuss the current knowledge of the paleobiogeography of Alligatoroidea in Europe during the Paleogene. Arambourgia gaudryi was likely part of a group of small early globidontans that arrived in the Old World, probably from North America, around the end of the Paleocene and that dispersed to at least four localities of the ancient European archipelago. [ABSTRACT FROM AUTHOR]

The Paleocene deposits from the Cerrejón Formation (Colombia, South America) have provided abundant snake remains. All this material has been assigned to the giant snake Titanoboa cerrejonensis. Here, we describe six vertebrae from among the referred materials that do not correspond to Titanoboa. All six vertebrae are morphologically identical, of a similar size, and display a distinct morphology that differs from Titanoboa. This new and unnamed taxon is a large snake estimated to be around eight meters in total length. Anatomical comparisons show that these vertebrae possess certain features typical of the Palaeophiidae, a group of extinct snakes of uncertain relationships known almost exclusively from vertebrae. Among the Palaeophiidae, the new taxon resembles the more generalized forms assigned to the genus Palaeophis, but lacks the extreme aquatic adaptations that define forms assigned to the genus Pterosphenus. We regard the new taxon as an undetermined palaeophiine but do not assign it to Palaeophis as a number of features differ from that described genus. This new record expands the known diversity of aquatic snakes from the Paleogene of South America and provides a substantial new record for the paleogeographic distribution of the Palaeophiidae. The oldest records are from the Cretaceous of Africa, while Paleocene records are poorly known and restricted to Africa, North America, and Europe. The majority of vertebral forms assigned to Palaeophiidae are from the Eocene, principally from the Tethys region, with only one previous South American record coming from the Eocene of Ecuador. [ABSTRACT FROM AUTHOR]

The earliest phases of mammalian recovery following the Cretaceous–Paleogene (K–Pg) mass extinction are incompletely known but crucial to understanding the development of modern terrestrial ecosystems. Here we report new mammalian faunal data from three vertebrate microfossil assemblages in the Hell Creek region of northeastern Montana, the deposition of which we constrain to within the first 28–80 ka of the Paleocene using new stratigraphic observations within a high-resolution chronostratigraphic framework. We quantified the taxonomic diversity among these three assemblages and five other assemblages from both the Hell Creek region and Denver Basin, together spanning the first ca. 300 ka post-K–Pg mass extinction. Our results allowed us to sub-divide the established 'disaster' and 'recovery' phases of recovery into the following sub-phases: (i) early disaster, characterized by the presence of 'dead clades walking,' high relative abundance of bloom taxa, and the appearance of post-mass-extinction immigrants, (ii) late disaster, characterized by a reduction in the number of 'dead clades walking,' continued high relative abundance of bloom taxa, and a more diverse assemblage of immigrants, (iii) early recovery, characterized by decreased relative abundance of bloom taxa, and continued immigration, and (iv) late recovery, characterized by the onset of in situ diversification. We note important differences in the pattern and timing of mammalian faunal succession between the Hell Creek and Denver Basin, suggesting that post-K–Pg mammalian recovery was spatially heterogeneous. Our results provided a new model for post-K–Pg mammalian biotic recovery that can now be tested with other earliest Paleocene assemblages across western North America. [ABSTRACT FROM AUTHOR]

Reported here is the discovery of a new mammal from the middle Paleocene of the Ouled Abdoun phosphate basin, Morocco. Hadrogeneios phosphaticus, gen. et sp. nov., is described based on dental and gnathic specimens. Comparative dental anatomy and CT scan observations support stem relationships to paenungulates. The cladistic analysis relates Hadrogeneios to paenungulatomorphs, especially based on the shared morphotypic condition of a dilambdodont ectoloph linked to inflated stylar cusps. Within the Paenungulatomorpha, Hadrogeneios is plesiomorphic not only with respect to crown paenungulates, but also to Abdounodus and Ocepeia, making it the basalmost known paenungulatomorph. Hadrogeneios, on the other hand, displays a peculiarly specialized mandibular symphyseal region (mentum), which is enlarged and raised high above the cheek teeth, and bears at its apex small incisors that are innervated and vascularized by a peculiar long and thin dorsal canaliculus. This is tentatively interpreted as a plier-like dental apparatus specialized for enhanced oral gripping function of the food, with increasing grip strength or enhanced grip precision. A composite reconstruction of the lower jaw of Hadrogeneios phosphaticus, based on 3D modeling from CT scans, is provided. Hadrogeneios, Abdounodus, and Ocepeia, all from the same Ouled Abdoun Paleocene phosphate levels, are the very rare witnesses of the first evolution and diversification of the endemic African ungulates phylogenetically preceding the modern paenungulate orders. [ABSTRACT FROM AUTHOR]

The Madtsoiidae are an extinct lineage of snakes known from the Late Cretaceous to the Late Pleistocene, with a rich fossil record distributed mainly across Gondwanan landmasses. However, only a few taxa are represented by cranial or articulated remains, and most madtsoiids are known only by isolated vertebrae. The unambiguous record of Madtsoiidae from the Cenozoic in South America had been restricted to the genus Madtsoia from Eocene and Oligocene deposits of Patagonia and Brazil. Here, we describe a new madtsoiid taxon, Powellophis andina gen. et sp. nov., based on an articulated postcranial skeleton from the Mealla Formation (middle–late Paleocene) in northwestern Argentina. The new taxon is estimated to be around 3 meters long, with a vertebral morphology sharing similar features with other mid-to-large forms. Its inclusion in a recent analysis of madtsoiid relationships recovers Powellophis as an early member of a clade formed by mostly large bodied and gigantic taxa. Its presence in the Paleocene of northwestern Argentina fills the gap between the diverse Late Cretaceous and Eocene–Oligocene records of madtsoiids in South America, confirms their presence in northern Gondwana by the early Paleogene, and expands the diversity of the group. [ABSTRACT FROM AUTHOR]

Xenarthra are an endemic and relictual clade of Placentalia that played an important role in the biodiversity during the Cenozoic in today South America. Fossil forms representing close to 200 genera have been identified, both Pilosa and Cingulata, during its long evolutionary history (late Paleocene/early Eocene–Recent). However, there is an evident imbalance in what concerns the knowledge of the xenarthrans of southern South America compared with those of middle and low latitudes, of which little is known, despite the fact that in recent times the studies of these latter have been greatly improved. New remains of Xenarthra (Folivora Mylodontinae gen. et sp. indet. and Cingulata Glyptodontidae gen. et sp. indet.) from the Letrero Formation, upper Miocene (ca. 11–9 Ma, Tortonian) of southern Ecuador are here reported and described. The only previous record from this formation belongs to the Cingulata Dasypodidae Anadasypus aequatorianus. Our comparative study reveals several morphological differences compared with other known Miocene specimens, especially those of La Venta (Colombia), Anzoátegui and Urumaco (Venezuela), and the Patagonian region (Argentina). These morphological differences suggest that these remains could belong to new taxa, and highlight the fact that, despite the relative proximity, both chronological and geographic, of the middle Miocene of La Venta (Colombia, ca. 13–11 Ma, Serravallian to Tortonian), the Xenarthra registered in Ecuador are morphologically distant, suggesting some isolation of this putative endemic paleofauna. [ABSTRACT FROM AUTHOR]

A new crocodyliform, Sebecus ayrampu, sp. nov., is described based on the rostral region of the skull, mandibular rami, and a distal portion of the femur collected in Paleocene rocks of northwestern Argentina. The new taxon is diagnosed (among other characters) by the presence of a sharp sagittal torus on the palatal surface of the premaxilla and maxilla, the surface of the alveolar region of the premaxilla descending vertically with respect to the palatal surface of the maxilla and the rest of the premaxilla, deep premaxillary fossa for the hypertrophied mandibular tooth with a ridge along its anterior margin, a differential pattern of ornamentation of the rostrum external surface, and a V-shaped anterior margin of the choana (with the vertex pointing anteriorly). This specimen is recovered as a new member of Sebecidae in a phylogenetic analysis, increasing the taxonomic diversity of the group in the Paleogene of northwestern Argentina. A sensitivity parsimony analysis using equal and implied weights (with different K values) retrieves two distinct lineages within Sebecidae: the Ayllusuchus + Bretesuchus clade and the Sebecus clade (in which the new taxon is included). Sebecidae is also recovered as a sister group to Baurusuchidae, forming together the monophyletic Sebecosuchia within Notosuchia. [ABSTRACT FROM AUTHOR]

The diversity of fishes represented in upper Paleocene microfossil localities in the Ravenscrag Formation near Roche Percée, Saskatchewan, is documented. Thirteen kinds of fishes are recognized. Two chondrosteans are present, a sturgeon and a paddlefish, both represented by small, irregularly shaped, ornamented bony plates. Four kinds of basal neopterygians are identified. Two of these, Atractosteus and Cyclurus, are widely distributed in both Paleocene and Upper Cretaceous localities. The remaining two are unnamed taxa designated Holostean A and Holostean B that were known previously from Upper Cretaceous localities but have not been reported from the Paleocene prior to this report. The presence of these taxa in the late Paleocene further supports the conclusion that basal neopterygians were little affected by the K/Pg mass extinction event. Seven teleosts are present in the assemblage. This assemblage of teleosts is similar to assemblages of upper Paleocene fishes from the Paskapoo Formation of Alberta in the presence of osteoglossomorphs, a gonorhynchiform, the esocid Esox, a percopsiform, and at least one other acanthomorph. It differs in the presence of a generically indeterminate protacanthopterygian designated here as morphotype ES-1 and a teleost of uncertain relationships designated morphotype PT-1. Neither of these taxa is present in the Late Cretaceous, suggesting that they first appeared in the area during the early or middle Paleocene. Comparison of the fish assemblages of the late Paleocene and early Eocene suggests that a major faunal transition occurred at the Paleocene/Eocene boundary, and that this involved a decrease in diversity of basal neopterygians. [ABSTRACT FROM AUTHOR]

Baenidae are the most diverse clade of turtles from the latest Cretaceous and earliest Paleogene of North America. Palatobaena species have a distinctive cranial bauplan within baenid turtles and we herein describe a new species, P. knellerorum, based on a complete cranium from the lower Paleocene Denver Formation in the Denver Basin, Colorado. Palatobaena knellerorum differs from other Palatobaena species in the extreme degree of its dorsally oriented orbits, as well as the presence of a broad pentagonal midline crest formed by the supraoccipital and parietals. It can be further diagnosed from other species of Palatobaena by the following unique combination of characters: having a broadly rounded cranium, presence of upper temporal emargination that extends well anterior to the otic chamber, a broad exposure of the supraoccipital on the dorsal skull roof, a broadly rounded 'tongue groove' between the maxillae and premaxillae, and a deeply emarginated nasal region that exposes the underlying premaxillae in dorsal view. Palatobaena knellerorum most closely resembles the Maastrichtian/Danian taxon Palatobaena cohen and the Danian taxon P. bairdi. A phylogenetic analysis places P. knellerorum as sister to P. bairdi, and these taxa are sister to P. cohen. Palatobaena knellerorum overlaps in time with P. cohen, but the two are separated geographically with P. knellerorum restricted to the Denver Basin and P. cohen restricted to the Williston Basin. Cranial anatomical data and sedimentological data suggest Palatobaena spp. were bottom dwelling turtles living in shallow water environments that used a putative proboscis to prey upon freshwater-shelled invertebrates. [ABSTRACT FROM AUTHOR]

North American soft-shelled turtles, including trionychines and plastomenids, are incredibly abundant in latest Cretaceous through earliest Paleocene sediments. Here we describe a new species of plastomenid turtle, Plastomenus joycei, based on a nearly complete early Danian skeleton from the Denver Formation in the Denver Basin, Colorado. Plastomenus joycei is differentiated from all other plastomenid turtles based on the presence of large eighth costals that are much longer than wide, sinusoidal raised ridges on the carapace, flat posterior edge of the carapace, spike-like epiplastra that lack callosities, a broad entoplastron that lacks a callosity, hyoplastra with two lateral processes, presence of metaplastically ossified hyoplastral shoulders (i.e., anteriorly protruding lappets), and a broad midline contact between the hypo- and xiphiplastra. Plastomenus joycei broadly resembles the Cretaceous Gilmoremys spp. and the Eocene Plastomenus thomasii and exhibits intermediate morphology between the two, most notably in the degree of ossification of the plastron. The increase in plastral ossification, as well as a decrease in overall size and an increase in the doming of the shell, co-occurs with the Cretaceous–Paleogene mass extinction and these morphological changes may be in response to an increase in mammalian predators during the early Paleogene. Plastomenus joycei is most commonly found in riverine sandstone sediments and is hypothesized to be a riverine turtle. [ABSTRACT FROM AUTHOR]

ABSTRACT—The skull of the Paleocene mammalRadinskyais redescribed here, based on direct study of the type and only specimen. A number of inaccuracies from previous studies are corrected.Radinskyapossesses two potential synapomorphies with perissodactyls, namely, posteriorly broad nasals and a small, laterally facing exposure of the mastoid process of the periotic. The phylogenetic position ofRadinskyais examined using matrices from three studies, two that originally includedRadinskyaand for which the scores forRadinskyaare corrected, and another recent study of archaic ungulates that did not originally includeRadinskya. In addition, a new analysis is performed combining data from all three previous studies, including modifications based on the present study. Reanalyses of the three previous studies give conflicting results regarding the issue of perissodactyl ancestry, placingRadinskyaas sister taxon to perissodactyls, as sister taxon to a perissodactyl-phenacodontid clade, or as part of a polytomy with perissodactyls and paenugulates. The results of the new analysis (1) place perissodactyls closer toRadinskyathan to phenacodontids; (2) place Hyracoidea and Proboscidea (i.e., Paenungulata) as sister taxa to Perissodactyla; (3) do not support inclusion ofRadinskyain Phenacolophidae; and (4) are equivocal in placingLophocionas the phenacodontid closest to perissodactyls. These results thus support neither an Asian nor a North American origin for perissodactyls. Future studies should examine the origins of perissodactyls and other ‘ungulates’ in a broader taxonomic context, in order to more directly address discrepancies between results supported by morphological data and those derived from molecular data. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP [ABSTRACT FROM AUTHOR]

Geological investigation of the Boyabat Basin in north-central Anatolia, Turkey, yielded palaeoamasid (Embrithopoda, Mammalia) gnathodental fossil specimens from two localities dated to the Eocene–Oligocene transition. These specimens include an upper incisor (BOY-1) and maxillary fragment preserving M2–M3 (BOY-2), and are geologically the youngest embrithopods known from Eurasia. The maxillary specimen is taxonomically more useful and, among embrithopods preserving the same molars, is most similar to the late Paleocene–middle Eocene Turkish palaeoamasidPalaeoamasia kansui. However, the new specimens are cautiously classified asPalaeoamasia, sp. nov., based on distinctions between BOY-2 andP. kansuiin M3 morphology. Features distinguishing the M3 in BOY-2 are intermediate between those ofP. kansuiand the more derived Afro-Arabian arsinoitheriid embrithopodsArsinoitheriumspp. andNamatherium blackcrowense, although the new Turkish specimens are stratigraphically too young to be ancestral to these middle Eocene–late Oligocene arsinoitheriids. Salient differences in dental and gnathic morphology between contemporaneous Eurasian and Afro-Arabian embrithopods indicate long, separate phylogenetic trajectories for these taxa, supporting the view that they are divisible at the family level into Palaeoamasidae and Arsinoitheriidae, respectively. Improved documentation of the lengthy paleogeographic separation of palaeoamasids and arsinoitheriids confirms that Afro-Arabia was sufficiently isolated from Eurasia during the Paleogene to limit embrithopods to rare sweepstakes dispersal between these landmasses. [ABSTRACT FROM AUTHOR]

Procreodi is an order of Paleocene and Eocene mammals thought to lie at the base of the radiation of the paraphyletic ‘condylarths.’ Taxa within the order have been linked to the origins of other condylarth groups, and of some living orders. Within the order, there are specializations indicative of a range of behaviors, and a considerable size range including some of the largest Paleocene mammals.Arctocyon mumakis the largest known arctocyonid. Several craniodental specimens from the Tiffanian of western North America and one partial skeleton, preserving parts of the fore- and hind limbs, pelvic and pectoral girdles, and some vertebrae, with associated teeth and other bony elements, are described here for the first time. Skeletal elements ofA. mumakare larger than those of other species ofArctocyonandAnacodon, but are otherwise similar in overall morphology. Certain features of the tarsus, such as the large plantar tubercle on the navicular and the well-developed groove below the sustentaculum tali, are shared betweenA. mumakandAnacodonto the exclusion ofArtcocyonand are suggestive of plantigrady and a degree of fossoriality. Univariate and multivariate statistical analyses of six ecomorphological ratios successfully distinguishes a taxonomically diverse group of 47 extant taxa with differing locomotor specializations. When calculated forArctocyon mumak, these ratios support the view that this taxon was a terrestrial, possibly semi-fossorial taxon. Other taxa within Procreodi are recovered as more arboreal or more terrestrial. Significant ecological and morphological variation exists within this understudied group. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP [ABSTRACT FROM AUTHOR]

We evaluate new lungfish remains from the Upper Cretaceous Quseir Formation in the Western Dessert of southern Egypt. Taxa includeLavocatodus protopteroides,L. humei,L. giganteus, andProtopterus nigeriensis.We treatLavocatodusas members of Lepidosirenidae based on the presence of a well-defined medial articular surface, in the absence of a symphyseal surface of corresponding prearticular bones. Material ofL. protopteroidesrepresents the first example of an adult specimen, supporting the retention of the species as valid, and not a junior synonym ofL. humei. Specimens ofL. humeiare the most abundant in the assemblage, and all exhibit the medial articular surface, a feature that is absent from specimens ofCeratodus; therefore, we reassign additional specimens of ‘C.’humeitoLavocatodus. New specimens ofL. giganteusextend the temporal and spatial ranges of the species (the type material ofL. giganteusis from Paleocene deposits of In Farghas, Mali). Finally, a new specimen ofProtopterusrepresents the oldest record of the genus in Egypt. The prearticular is confidently assigned toProtopterusbased on the presence of only three ridges on the tooth plate, a medial symphyseal suture, a coronoid process, and a shallow tooth crown plus prearticular depth. We further assign it toP. nigeriensisbased the length and merger of tooth ridges. Furthermore, the oldest Cenomanian specimens reported from the Sudan Wadi Milk Formation are assigned toP. nigeriensis, which would extend the temporal range ofP. nigeriensisby roughly 14 Ma. [ABSTRACT FROM AUTHOR]

The article presents a research study which describes metatherians from members 4a and 4b of the Goler Formation in California and their impact on Paleocene metatherian paleobiogeography in western North America. Topics discussed include the description of the referred specimens, Peradectes and Golerdelphys stocki, holotypes, and diagnosis. Also provided is information regarding the results of phylogenetic analysis of the species.

We describe a new avian species,Qianshanornis rapax, gen. et sp. nov., from the middle Paleocene Wanghudun Formation of the Qianshan Basin in Anhui Province, China. The holotype consists of an incomplete articulated foot and a few associated bones, mainly of the leg, wing, and pectoral girdle.Qianshanornis rapaxis characterized by a derived foot morphology and may have had a hyperextendible second toe, which has so far only been reported for some Mesozoic taxa. The new species is markedly different from all other known Cenozoic birds and is here classified in the new taxon Qianshanornithidae. The leg bones, especially the distal end of the tibiotarsus, most closely resemble those ofStrigogyps(Ameghinornithidae) from the Eocene, and possibly Oligocene, of Europe, but unlike the latter, the much smallerQ. rapaxappears to have had well-developed flight capabilities. [ABSTRACT FROM PUBLISHER]

‘Arctocyonids’ are generally considered as including some of the most primitive ‘ungulates’ from the Paleocene. Although more than 15 genera are known from North America, European members of this order are less common and mainly belong to derived genera such asArctocyon. However, one species of primitive arctocyonid,Prolatidens waudruae, was described from the early Paleocene of Hainin, Mons Basin, Belgium. Here we describe new dental positions of this small taxon, including for the first time upper molars and upper fourth premolar. Morphological comparisons confirm the position ofP. waudruaeamong primitive ‘ungulates,’ with the closest North American arctocyonids beingProthryptacodon furensandOxyprimus galadrielae.Oxyprimus galadrielaefeatures slightly more primitive morphological traits than both other species. Apheliscids share several characters withProlatidens, but the latter lacks the apomorphies defining the family. Among ‘arctocyonids,’Prolatidensshares with onlyProtungulatumandOxyprimusthe incomplete lingual cingulum at the base of the protocone of M1.Prolatidens waudruaeis unique among Procreodi in its combination of primitive and derived characters. The cladistic analysis placesP. waudruaeclose to the base of the ingroup, indicating that this species is among the most primitive members of the Paleocene ‘ungulates.’ However, the lower nodes of the trees are not well supported and definitive conclusions should await more complete specimens and analysis. Apheliscids are situated relatively far fromProlatidens, suggesting that the resemblances between them are better considered as convergences. Based on the morphological comparisons, the arctocyonid from Hainin correlates best with North American Torrejonian taxa. [ABSTRACT FROM PUBLISHER]

We describe the earliest petrosal bone referred to the South American endemic Notoungulata, from the late Paleocene-early Eocene Beds of Itaboraí, which provides a critical basis for assessing their enigmatic origins. As indicated by our phylogenetic analysis, the fossil belongs to a taxon most likely close to the ancestral root of the Notoungulata. We describe the entire external anatomy of this isolated ear bone and also investigate the bony labyrinth of the inner ear through computed tomographic scan reconstruction. Within Notoungulata, the specimen retains a number of features considered plesiomorphic, such as a narrow medial flange on the tympanic surface, the presence of a petromastoid canal, and a rather deep fossa subarcuata. We also present a survey of the petrosal anatomy of early diverging notoungulates compared with other members of Eutheria. Features regarded as plesiomorphic in Notoungulata comprise a low stapedial ratio, a cavity for the trigeminal ganglion, a secondary crus commune, a ramus superior of stapedial artery (although reduced) and arteria diploëtica magna, and the tegmen tympani pierced by a canal. Derived features include notably a laterally located tensor tympani fossa, a bean-shaped promontorium and adjoining flattened medial flange, and a stapedial fossa poorly separated from the postpromontorial tympanic sinus. A number of derived notoungulate characters are interestingly shared with the extant hyraxProcavia. Further investigation of this anatomical region in other eutherians is required in order to fully exploit the phylogenetic potential of our new observations. This is especially needed for other groups of South American endemic ungulates possibly related to Notoungulata. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP [ABSTRACT FROM PUBLISHER]

Choristodera is a clade of freshwater aquatic reptiles with a strictly Laurasian distribution and a temporal record extending from at least Middle Jurassic to Miocene. The large Cretaceous–Eocene neochoristoderesChampsosaurusandSimoedosaurusare the most familiar taxa, but many smaller representatives have since been recognized. Neochoristoderes disappeared from the fossil record in the Eocene, but choristoderes survived into the European Neogene in the form of the small, superficially lizard-likeLazarussuchus. This taxon was originally described from the late Oligocene of France but has subsequently been recorded from the early Miocene of the Czech Republic and the late Oligocene of Germany. Despite its age, most phylogenetic analyses placeLazarussuchusat or close to the base of the choristoderan tree, implying a very long unrecorded history. A new specimen ofLazarussuchusfrom the late Paleocene locality of Menat, France, partly fills that hiatus. The genus was thus present in the waterways of western Europe for at least 30 Ma, and was probably considerably more widespread than current records suggest. A new phylogenetic analysis confirms its placement outside Neochoristodera, but the relationships of non-neochoristoderan taxa remain incompletely resolved. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP [ABSTRACT FROM PUBLISHER]

The article focuses on the documentation of Kimbetohia Campi from early Paleocene strata in the North Horn Formation of Utah. It states that the specie was first known in New Mexico and it was described by several paleontologists based on its skull fragment and physical features. It chronicles the discovery of the specie in the area in 2006 through several locality and assessment of its biostratigraphic importance of occurrence. It describes the characteristics and physical features of the specie, as well as its assigned codes.

Ernanodon, one of the most enigmatic Asian fossil mammals, was previously known by a single specimen from the late Paleocene (Nongshanian) of China. Here we document the first record of Ernanodon from Mongolia, represented by a nearly complete skeleton from the late Paleocene (Gashatan) of the Naran Bulak locality. The new material provides an opportunity to understand the lifestyle and habits of this rare mammal and reevaluate the arguments used to establish the phylogenetic relationships of Ernanodon. Functional analysis indicates that Ernanodon had very strong forelimbs with large claws and used its forelimbs for scratch-digging. Character analysis reveals numerous similarities in postcranial anatomy between Ernanodon and Palaeanodonta. Phylogenetic analysis supports inclusion of Ernanodon in the order Palaeanodonta and suggests that Palaeanodonta and Pholidota are sister groups. [ABSTRACT FROM AUTHOR]

Fossil soft-shelled turtles (Trionychidae) have so far been recognized in all continents except Antarctica, based largely on remains preserving their diagnostic sculptured shell bones. The origin of the group is generally assumed to be in the Early Cretaceous of Asia, whereas they first appear in North America and Europe during the Late Cretaceous and Paleocene, respectively. Here we describe the first record of an indeterminate trionychid from the late early Campanian from southern Sweden, a part of the paleobiogeographically isolated Fenno-Scandian Shield, thus extending the stratigraphic record of the group in Europe back about 15 Ma into the Late Cretaceous. Our finding provides evidence against the currently favored dispersal scenario in which trionychid turtles are interpreted to have come to Europe first during the Paleocene either directly from North America or via Asia. The described indeterminate trionychid possibly represents a relic of a pre-Cretaceous endemic radiation of North European trionychids living mainly on the Fenno-Skandian Shield or it may indicate a potential lower latitude dispersal route of trionychids from Asia to North America via Europe during the Late Cretaceous. [ABSTRACT FROM AUTHOR]

Plesiadapidae are among the most successful mammal families of the Paleocene, but in North America they disappear abruptly around the Paleocene-Eocene boundary. In contrast, in Europe, they survive a few million years into the Eocene, although only as the genus Platychoerops. The latest Paleocene deposits of Petit-Pâtis (Paris Basin, France) have produced three new plesiadapid species, one of each genus known in Europe: Plesiadapis ploegi, sp. nov., Platychoerops boyeri, sp. nov., and Chiromyoides mauberti, sp. nov. Each of these new species is represented by the very characteristic upper incisor, thus ascertaining their concomitant presence and in particular the spatial and temporal coexistence of Plesiadapis and Platychoerops. Plesiadapis ploegi, sp. nov., is morphologically intermediate between Plesiadapis tricuspidens and Platychoerops russelli, with a tricuspid I1 typical of Plesiadapis and a semimolariform p4 closer to Platychoerops. Its relatively high morphological variability is illustrated. Platychoerops boyeri, sp. nov., has the simple derived I1 of all Platychoerops and a p4 slightly more molariform than that of Ples. ploegi. Chiromyoides mauberti, sp. nov., is closest to Chiromyoides campanicus, but it is smaller and has a particular I1 with multiple posterocones. The systematic position of ‘Platychoerops’ georgei is discussed; this taxon is considered a chimera, and its type I1 belongs to either Chiromyoides or Plesiadapis. Cladistic analysis highlights the paraphyly or polyphyly of all genera of Plesiadapidae. Finally, there is some indication of morphological convergences between European and North American plesiadapids, which may be the result of similar environmental changes on both continents just before the Paleocene-Eocene boundary. http://zoobank.org/urn:lsid:zoobank.org:pub:A73AEFC3-AA93-4EB6-8BD2-E3B15515C6FB SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: De Bast, E., C. Gagnaison, and T. Smith. 2018. Plesiadapid mammals from the latest Paleocene of France offer new insights on the evolution of Plesiadapis during the Paleocene-Eocene transition. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1460602. [ABSTRACT FROM AUTHOR]

We describe a partial skeleton of a new stem group representative of the Sphenisciformes from the mid-Paleocene Waipara Greensand in New Zealand, which represents the best-preserved and most complete Paleocene penguin found so far. Sequiwaimanu rosieae, n. gen. et sp., is the fourth penguin species from the Waipara Greensand, which previously yielded two species that were assigned to the taxon Waimanu, in addition to leg bones of an unnamed giant penguin. Among other features, the new species is characterized by an articular facet for the furcula on the apex carinae of the sternum, which is unknown from other sphenisciforms. We perform detailed comparisons with the species assigned to Waimanu and show that the type species Waimanu manneringi differs in tarsometatarsus morphology from its putative congener ‘W.’ tuatahi, which is here assigned to the new taxon Muriwaimanu. Sequiwaimanu rosieae exhibits a more derived morphology than Muriwaimanu tuatahi, but its exact affinities to W. manneringi are unresolved owing to the incompletely known osteology of the latter species. With S. rosieae being more closely related to the crown group than M. tuatahi, shared characteristics of the two taxa are likely to be plesiomorphic for sphenisciforms. Although the skeletal morphology of these sphenisciform stem species shows some similarities to plotopterids (i.e., wing-propelled diving seabirds from the North Pacific Basin) in some characters, the stem group sphenisciforms from the Waipara Greensand are clearly distinguished from plotopterids.http://zoobank.org/urn:lsid:zoobank.org:pub:86031231-EADB-45EF-930B-8E55833D32F6SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Mayr, G., V. L. De Pietri, L. Love, A. A. Mannering, and R. P. Scofield. 2018. A well-preserved new mid-Paleocene penguin (Aves, Sphenisciformes) from the Waipara Greensand in New Zealand. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1398169. [ABSTRACT FROM AUTHOR]

Kelemejtubus castroi, gen. et sp. nov., is described based on six specimens from the marine Danian deposits exposed in the Belisario Domínguez and División del Norte quarries, both located near Palenque City, Chiapas, México. Kelemejtubus castroi shows sufficient features to support its inclusion into the series Percomorpha and is diagnosed by the unique combination of an elongated maxillary, reaching the posterior portion of the orbit; the premaxillary and dentary bearing a row of stout conical teeth; an anterior longer canine-like tooth in the lower jaw; no supramaxillary; preopercle with three antrorse spines on its ventral portion; opercle with two posterior spines; absence of dorsal and anal fin stays; two slightly separated dorsal fin lobes, the first with nine spines and the last with one spine plus nine rays; an anal fin composed of two anal spines and seven soft rays; one supernumerary spine on the first anal pterygiophore; 24 vertebrae, with 10 being abdominal; a caudal fin formula I+8-7+I; three epurals; and a slightly forked posterior ventral procurrent ray with a spur. The absence of unique derived characters, however, does not allow its assignment to any subgroup; thus, it is considered here as a percomorph incertae sedis. This taxon increases the knowledge about the fish assemblage that lived in marine environments at the extreme south of North America approximately 63 million years ago, just after one of the most catastrophic massive extinctions responsible for drastic changes in biodiversity.Citation for this article: Cantalice, K. M., and J. Alvarado-Ortega. 2017. Kelemejtubus castroi, gen. et sp. nov., an ancient percomorph (Teleostei, Actinopterygii) from the Paleocene marine deposits near Palenque, Chiapas, southeastern Mexico. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1383265. [ABSTRACT FROM AUTHOR]

Plastomenidae is a speciose clade of soft-shelled turtles (Trionychidae) known from Campanian to Eocene deposits throughout western North America. We here describe two large skulls from the Upper Cretaceous (Maastrichtian) Hell Creek Formation of Carter County, Montana, that document the adult morphology of the plastomenidGilmoremys lancensis. Whereas juveniles of this species, as previously documented by five subadult skulls, have narrow skulls, a narrow processus trochlearis oticum, a deep and narrow median palatal groove, low accessory ridges, and a secondary palate fully formed by the maxilla, skeletally mature individuals have notably broad skulls, a broad processus trochlearis oticum, a shallow but broad median palatal groove, high accessory ridges, and a substantial contribution of the vomer to the secondary palate. An expanded phylogenetic analysis reveals that the CampanianAspideretoides foveatusand the PaleoceneAspideretoides superstes, nov. comb., are situated within Plastomenidae as sister to all previously identified plastomenid turtles, despite their general resemblance to trionychine soft-shelled turtles. The nameAspideretoidesshould therefore not be used as a taxonomic wastebasket for fossil trionychids with unclear phylogenetic relationships. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP Citation for this article: Joyce, W. G., T. R. Lyson, and S. Williams. 2016. New cranial material ofGilmoremys lancensis(Testudines, Trionychidae) from the Hell Creek Formation of southeastern Montana, U.S.A. Journal of Vertebrate Paleontology, e1225748. DOI: 10.1080/02724634.2016.1225748. [ABSTRACT FROM PUBLISHER]

We report the discovery of the earliest European carnivoraforms, based on two new taxa from the latest Paleocene of France and Romania. A new species of Vassacyon, V. prieuri, from the locality of Rivecourt (MP6b; Oise, France) (MP = Mammalian Paleogene reference levels) is described based on a dentary fragment and isolated teeth. This species displays several primitive features compared with species of Vassacyon known from the early Eocene of North America and Europe. A second Paleocene carnivoraform, cf. Gracilocyon sp., is described based on fragmentary specimens from the locality of Jibou (MP6b; Transylvania, Romania). Carnivoraformes were previously unknown in Europe before the Eocene, and Vassacyon prieuri and cf. Gracilocyon sp. are their oldest records in Europe. These discoveries favor the hypothesis of a dispersal of these two genera from Europe to North America during the Paleocene-Eocene Thermal Maximum. Vassacyon prieuri and cf. Gracilocyon sp. strengthen support for the level MP6b and its correlation with the Clarkforkian. The geographic origin of the Carnivoraformes remains unknown. However, based on the observed biochronological and geographic distributions of the carnivoraforms, we infer a possible Asian origin for this group. In this scenario, Gracilocyon and Vassacyon dispersed to Europe during the Clarkforkian MP6b time, probably together with rodent taxa, whereas Uintacyon dispersed from Asia to North America shortly after rodents and tillodonts. http://zoobank.org/urn:lsid:zoobank.org:pub:FC885E7F-877A-4454-9902-DF118B8C8693 SUPPLEMENTAL DATA—Supplemental materials are available forthis article for free at www.tandfonline.com/UJVP Citation for this article: Solé, F., T. Smith, E. de Bast, V. Codrea, and E. Gheerbrant. 2016. New carnivoraforms from the latest Paleocene of Europe and their bearing on the origin and radiation of Carnivoraformes (Carnivoramorpha, Mammalia). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1082480. [ABSTRACT FROM AUTHOR]

Gomphochelys nanus, new genus and species, is described from the earliest Wasatchian (biohorizon Wa 0; ∼55.8 Ma) of the southeastern Bighorn Basin, Washakie County, Wyoming. The new taxon represents the only known dermatemydid from the Paleocene–Eocene Thermal Maximum (PETM) interval and extends the lineage back from previous records by approximately 2 million years.Gomphochelys nanushas a thick tricarinate carapace and differs from other dermatemydids in attaining a smaller adult body size, having reduced plastral features, a posteriorly situated gular–humeral sulcus, an acarinate pygal, and thick shortened peripherals. Reexamination of previously described fossil dermatemydids suggests that the taxaBaptemys tricarinataandKallistira costilataare junior synonyms of the middle–late WasatchianNotomorpha garmanii, andBaptemys fluviatilisis likely a junior synonym ofBaptemys wyomingensis.Gomphochelys nanusis a stem dermatemydid that is similar toN. garmaniibut differs in possessing symplesiomorphies with the Late Cretaceous–Paleocene generaAgomphusandHoplochelys. Aspects of shell morphology suggest thatG. nanuswas a commensurate swimmer and bottom-walker like extantDermatemysandStaurotypus. The presence of a dermatemydid (a tropically distributed clade) in the southeastern Bighorn Basin during the PETM (when global temperatures increased by 5°C–10°C over a period of ∼60 ky) further supports the hypothesis that climate was megathermal in the region during this interval and is consistent with previously documented geographic range changes in both plants and animals. Dermatemydids disappear from the fossil record at the end of the PETM and don't reemerge until the next warming event, Eocene Thermal Maximum 2. http://zoobank.org/urn:lsid:zoobank.org:pub:19A98079-5CAD-4BC5-8C21-2810AA576D98 SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP [ABSTRACT FROM PUBLISHER]