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Leptocyon douglassi, new species Figures 5, 6A–G, 7; appendix 3 Nothocyon geismarianus: Macdonald, 1970: 55. Type: NMNH 19931 (fig. 6C–E), cast AMNH 129685, partial palate with P4–M2 and left ramus with c and p2–m2 from the Toston Formation (early Arikareean), 2 2 miles southeast of Canyon Ferry, Lewis and Clark County, Montana. Etymology: Named for Earl Douglass whose pioneering studies of the fossil mammals of Montana initiated modern knowledge of the Neogene faunas of the northern Rocky Mountains. Referred Material: From the type area, Toston Formation (early Arikareean), Canyon Ferry, Lewis and Clark County, Montana: NMNH 19106 (cast AMNH 129684), fragments of immature skull and jaw including right partial ramus with p2 unerupted, dp3–dp4 and m2 unerupted, and left detached unworn m1. One mile east of Canyon Ferry: CMNH 1264, right and left mandibular rami with c–m3 (fig. 6A–B); and CMNH 1300, left ramus with i3 root, c–p3 alveoli, p4–m2, and m3 alveolus, Earl Douglass Collection, 1902. White Sulfur Springs (early Arikareean), Meagher County, Montana: F:AM 54196 (fig. 6F–G), left ramus with c broken and p1 alveolus, p2–m3 from deposits considered temporally equivalent to the Gering Formation by Schultz and Falkenbach (1949: 145). Wounded Knee–Sharps Fauna, Sharps Formation (early Arikareean), South Dakota: LACM 9371, left maxillary fragment with P4–M1 from LACM locality 1955 and referred to Nothocyon geismarianus by Macdonald (1970: 55); and LACM 9298, left maxillary fragment with M1 from LACM locality 1980. UCMP locality V6377, Haystack 8, L-2, Turtle Cove Member, John Day Formation, between the Picture Gorge Ignimbrite and Deep Creek Tuff (29–28 Ma, early Arikareean): UCMP 79365, anterior part of skull lacking canines and incisors, P1 alveolus, P2 roots, left P3, left and right P4, M1–M2. Distribution: Early Arikareean of Oregon, Montana, and South Dakota. Diagnosis: Leptocyon douglassi differs from all other Arikareean species by its derived p3 lacking posterior cusp, m2 with long talonid (.90% of trigonid length), and absence of m2 paraconid. Additionally, it differs from L. vulpinus in its smaller size and relatively narrower and lower crowned premolars; from L. gregorii in averaging smaller in size, M2 having metaconule, and P4 of greater width with stronger protocone; and from L. mollis in its smaller size and proportionally smaller M1 and M2. + Description and Comparison: The p2–p4 are widely spaced, elongate, slender, and moderately tall crowned. The lower premolars of the type ramus (NMNH 19931) and those of a referred ramus (F: AM 54196) have stronger anterior cingular cusps than in the type specimens of L. gregorii and L. vulpinus (compare figs. 6A–E with 11A–E and 8A–C). The anterior cusp is noticeably stronger on p3 and p4, and even the p2 of F:AM 54196 shows a small but distinct anterior cusp. Prominent anterior cingular cusp on the premolars is shared with Hesperocyon and members of the Borophaginae. On the other hand, the loss of a posterior cusp on P3 is a derived feature of this early Leptocyon species. The P4 of the type (NMNH 19931) is transversely thick with a large protocone and a weak parastylar shelf, similar to that of the type of L. mollis and L. vulpinus but unlike the slender upper carnassial of L. gregorii. The M1 is proportionally smaller than in L. mollis (fig. 5) but morphologically similar with an extremely low-crowned paracone and metacone, strong labial cingulum, and a strong parastyle. The M2 is also proportionally smaller than in the type L. mollis (fig. 5), but it is morphologically similar with an extremely low-crowned paracone and metacone, strong labial cingulum, and a strong parastyle. The M2 is also proportionally smaller than in the type and has a very lowcrowned paracone and metacone, a welldeveloped protocone, and a strongly recurved talon. The m1 is slender with a strong metaconid and a somewhat more basinlike talonid than in L. gregorii. The elongate m2 with a very long talonid contrasts with the shorter talonid length of the m 1 in L. gregorii and L. vulpinus. The m2 has a relatively large subequal protoconid and metaconid but lacks the distinct paraconid present in the type of L. vulpinus., Published as part of TEDFORD R. H., WANG X. & TAYLOR B. E., 2009, Phylogenetic Systematics Of The North American Fossil Caninae (Carnivora: Canidae), pp. 1-218 in Bulletin of the American Museum of Natural History 2009 (325) on pages 19-22, {"references":["Macdonald, J. R. 1970. Review of the Miocene Wounded Knee faunas of southwestern South Dakota. Bulletin of the Los Angeles County Museum of Natural History Science 8: 1 - 82.","Schultz, C. B., and C. H. Falkenbach. 1949. Promerycochoerinae: a new subfamily of oreodonts. Bulletin of the American Museum of Natural History 93 (3): 69 - 198."]}

Urocyon Baird, 1858 Type Species: Urocyon cinereoargenteus (Schreber), 1775. Included Fossil Species: U. progressus Stevens, 1965; U. minicephalus Martin, 1974; U. webbi, n. sp.; U. galushai, n. sp.; and U. citrinus, n. sp. Distribution: Medial Hemphillian to Recent in North America and Recent in Central America and northern South America. Revised Diagnosis: Differs from other vulpines in the following apomorphies: nasals extend posterior to the frontal-maxillary suture; larger more posterieorly extended depression on dorsal surface of postorbital process accentuated by parasagittal ridges that begin at postorbital processes; frontal crests lyrate, strongly ridged, and joining behind frontoparietal suture; frontal part of braincase more expanded with wider postorbital constriction; medial cusplets on I1–I2 absent; canines with short and little recurved crowns; anterolabial cingulum of P4 often produced as parastyle; m1 entoconid and hypoconid usually connected by cristids to form transverse crest, hypoconulid relatively large; m2 trigonid shorter with paraconid varying from small (U. citrinus) to absent, talonid narrower with hypoconulid varying from distinct cusp to shelf; and in derived species, horizontal ramus with subangular lobe, condyle above alveolar border, and shallow depression ventral to masseteric fossa. Discussion: Urocyon is considered the sister taxon of Metalopex. Unlike other vulpines, they have a protostylid on m1 and m2 and a strong labial cingulum on m2 that may be linked with the base of the welldeveloped protostylid. These synapomorphies are evidence of their phyletic relationship. As listed in the diagnosis, the morphology of the lower molars of Urocyon are more complex, with the consistent presence of the m1 protostylid, the entoconid and hypoconid being generally joined by a transverse crest, and the hypoconulid being larger. The m2 trigonid in Urocyon is very short with the paraconid generally absent, although there is a paracristid. In the most derived species of Urocyon, there is a shallow depression beneath the masseteric fossa, and a prominent subangular lobe is present, which may be keeled ventrally, strongly angled posteriorly, and spinose.

Eucyon Tedford and Qiu, 1996 Type Species: Canis davisi Merriam, 1911. Included North American Species: Eucyon davisi (Merriam), 1911, and E. ? skinneri, new species. Distribution in North America: Late Clarendonian of Nebraska and Hemphillian of Kansas, New Mexico, Oklahoma, Texas, Arizona, Nevada, Oregon, California, and northern Mexico. Revised Diagnosis: Eucyon has no autapomorphies but is distinguished from the fossil and living Vulpini and the Cerdocyonina by possession of synapomorphies also present in all other members of the Canina: frontal sinus invading base of postorbital process removing ‘‘vulpine-crease’’ or depression from dorsal surface of process; paroccipital process expanded posteriorly usually with salient tip; mastoid process enlarged as knob or ridgelike prominence; loss of foxlike lateral flare and eversion of dorsal border of orbital part of zygoma. Primitive characters retained by Eucyon relative to those of most species of Canis are: frontal sinus less posteriorly extended, ends anterior to frontoparietal suture and does not completely invade postorbital process; supraoccipital shield fan-shaped, inion broad and not strongly overhanging condyles; I3 less enlarged relative to I2 with weaker posteromedial cingulum; M1 paracone and metacone subequal in size; M2 metaconule weak or absent, postprotocrista present; m1 entoconid and hypoconid usually not joined by transverse crest; angular process of mandibular ramus less expanded with smaller fossa for inferior pterygoid muscle; forelimb short relative to hindlimb, radius/tibia ratio less than 80%; and humerus often with entepicondylar foramen. Derived features linking Eucyon with Canis include: zygomatic arch strongly arched rather than gently curved, and p4 with second posterior cusp. Discussion: In general, the morphology of Eucyon is similar to that of Vulpes, as they share numerous primitive features. However, Eucyon, like the South American cerdocyonines, possesses a small frontal sinus that does not fully penetrate the postorbital process, and it does not extend as far posteriorly as in most species of Canis. Eucyon does share with Canis species two synapomorphies lacking in the cerdocyonines, namely, the presence of a second posterior cusp on p4, and the strongly arched zygoma. In North America, Canis is not known until the late Hemphillian. Canis ferox Miller and Carranza-Castañeda (1998) tends to be morphologically intermediate between Eucyon davisi and Canis lepophagus. The former shows the derived enlargement of the frontal sinus that distinguishes it from E. davisi and supports its relationship to Canis., Published as part of TEDFORD R. H., WANG X. & TAYLOR B. E., 2009, Phylogenetic Systematics Of The North American Fossil Caninae (Carnivora: Canidae), pp. 1-218 in Bulletin of the American Museum of Natural History 2009 (325) on page 89, {"references":["Tedford, R. H., and Z. - X. Qiu. 1996. A new canid genus from the Pliocene of Yushe, Shanxi Province. Vertebrata Palasiatica 34: 27 - 48. [in Chinese with English summary]","Merriam, J. C. 1911. Tertiary mammal beds of Virgin Valley and Thousand Creek in northwestern Nevada. Part 2. Vertebrate faunas. Bulletin of the Department of Geology of the University of California 11: 199 - 304.","Miller, W. E., and O. Carranza-Castaneda. 1998. Late Tertiary canids from central Mexico. Journal of Paleontology 72: 546 - 556."]}

Urocyon Baird, 1858 Type Species: Urocyon cinereoargenteus (Schreber), 1775. Included Fossil Species: U. progressus Stevens, 1965; U. minicephalus Martin, 1974; U. webbi, n. sp.; U. galushai, n. sp.; and U. citrinus, n. sp. Distribution: Medial Hemphillian to Recent in North America and Recent in Central America and northern South America. Revised Diagnosis: Differs from other vulpines in the following apomorphies: nasals extend posterior to the frontal-maxillary suture; larger more posterieorly extended depression on dorsal surface of postorbital process accentuated by parasagittal ridges that begin at postorbital processes; frontal crests lyrate, strongly ridged, and joining behind frontoparietal suture; frontal part of braincase more expanded with wider postorbital constriction; medial cusplets on I1–I2 absent; canines with short and little recurved crowns; anterolabial cingulum of P4 often produced as parastyle; m1 entoconid and hypoconid usually connected by cristids to form transverse crest, hypoconulid relatively large; m2 trigonid shorter with paraconid varying from small (U. citrinus) to absent, talonid narrower with hypoconulid varying from distinct cusp to shelf; and in derived species, horizontal ramus with subangular lobe, condyle above alveolar border, and shallow depression ventral to masseteric fossa. Discussion: Urocyon is considered the sister taxon of Metalopex. Unlike other vulpines, they have a protostylid on m1 and m2 and a strong labial cingulum on m2 that may be linked with the base of the welldeveloped protostylid. These synapomorphies are evidence of their phyletic relationship. As listed in the diagnosis, the morphology of the lower molars of Urocyon are more complex, with the consistent presence of the m1 protostylid, the entoconid and hypoconid being generally joined by a transverse crest, and the hypoconulid being larger. The m2 trigonid in Urocyon is very short with the paraconid generally absent, although there is a paracristid. In the most derived species of Urocyon, there is a shallow depression beneath the masseteric fossa, and a prominent subangular lobe is present, which may be keeled ventrally, strongly angled posteriorly, and spinose., Published as part of TEDFORD R. H., WANG X. & TAYLOR B. E., 2009, Phylogenetic Systematics Of The North American Fossil Caninae (Carnivora: Canidae), pp. 1-218 in Bulletin of the American Museum of Natural History 2009 (325) on pages 68-69, {"references":["Stevens, M. S. 1965. A new species of Urocyon from the upper Pliocene of Kansas. Journal of Mammalogy 46: 265 - 269."]}

Eucyon Tedford and Qiu, 1996 Type Species: Canis davisi Merriam, 1911. Included North American Species: Eucyon davisi (Merriam), 1911, and E. ? skinneri, new species. Distribution in North America: Late Clarendonian of Nebraska and Hemphillian of Kansas, New Mexico, Oklahoma, Texas, Arizona, Nevada, Oregon, California, and northern Mexico. Revised Diagnosis: Eucyon has no autapomorphies but is distinguished from the fossil and living Vulpini and the Cerdocyonina by possession of synapomorphies also present in all other members of the Canina: frontal sinus invading base of postorbital process removing ‘‘vulpine-crease’’ or depression from dorsal surface of process; paroccipital process expanded posteriorly usually with salient tip; mastoid process enlarged as knob or ridgelike prominence; loss of foxlike lateral flare and eversion of dorsal border of orbital part of zygoma. Primitive characters retained by Eucyon relative to those of most species of Canis are: frontal sinus less posteriorly extended, ends anterior to frontoparietal suture and does not completely invade postorbital process; supraoccipital shield fan-shaped, inion broad and not strongly overhanging condyles; I3 less enlarged relative to I2 with weaker posteromedial cingulum; M1 paracone and metacone subequal in size; M2 metaconule weak or absent, postprotocrista present; m1 entoconid and hypoconid usually not joined by transverse crest; angular process of mandibular ramus less expanded with smaller fossa for inferior pterygoid muscle; forelimb short relative to hindlimb, radius/tibia ratio less than 80%; and humerus often with entepicondylar foramen. Derived features linking Eucyon with Canis include: zygomatic arch strongly arched rather than gently curved, and p4 with second posterior cusp. Discussion: In general, the morphology of Eucyon is similar to that of Vulpes, as they share numerous primitive features. However, Eucyon, like the South American cerdocyonines, possesses a small frontal sinus that does not fully penetrate the postorbital process, and it does not extend as far posteriorly as in most species of Canis. Eucyon does share with Canis species two synapomorphies lacking in the cerdocyonines, namely, the presence of a second posterior cusp on p4, and the strongly arched zygoma. In North America, Canis is not known until the late Hemphillian. Canis ferox Miller and Carranza-Castañeda (1998) tends to be morphologically intermediate between Eucyon davisi and Canis lepophagus. The former shows the derived enlargement of the frontal sinus that distinguishes it from E. davisi and supports its relationship to Canis.

PURPOSE: Right ventricular (RV) capacity to adapt to increased afterload is the main determinant of outcome in pulmonary hypertension (PH), a common morbidity seen in systemic sclerosis (SSc). We hypothesized that supine bicycle echocardiography (SBE), coupled with RV longitudinal systolic strain (RVLSS), improves detection of limitations in RV reserve in SSc. METHODS: 56 SSc patients were prospectively studied during SBE with RV functional parameters compared at rest and peak stress. We further dichotomized patients based on resting RV systolic pressure (RVSP) to determine the effects of load on contractile response. RESULTS: Our pooled cohort analysis revealed reduced global RVLSS at rest (−16.2 ± 3.9%) with normal basal contractility (−25.6 ± 7.7%) and relative hypokinesis of the midventricular (−14.1 ± 6.0%) and apical (−8.9 ± 5.1%) segments. With exercise, global RVLSS increased significantly (p=0.0005), however despite normal basal contractility at rest, there was no further augmentation with exercise. Mid and apical RVLSS increased with exercise suggestive of RV contractile reserve. In patients with resting RVSP < 35 mmHg, global and segmental RVLSS increased with exercise. In patients with resting RVSP ≥35 mmHg, global and segmental RVLSS did not increase with exercise and there was evidence of exertional RV dilation. CONCLUSION: Exercise provocation in conjunction with RVLSS identified differential regional contractile response to exercise in SSc patients. We further demonstrate the effect of increased loading conditions on RV contractile response exercise. These findings suggest subclinical impairments in RV reserve in SSc that may be missed by resting noninvasive 2DE-based assessments alone.

Speckle tracking echo is a useful clinical tool to distinguish differential RV contractility between PAH subtypeshttp://ow.ly/6Wyr30fVTeu