Cuenca-Bescos G.,University of Zaragoza |
Canudo J.I.,University of Zaragoza |
Gasca J.M.,University of Zaragoza |
Moreno-Azanza M.,University of Zaragoza |
Cifelli R.L.,Oklahoma Museum of Natural History
Journal of Vertebrate Paleontology | Year: 2014
Spalacotheriids, basal trechnotheres with an acutely angled, reversed-triangle pattern of major molar cusps, are relatively rare pan-Laurasian mammals that ranged through much of the Cretaceous but are generally not well represented in the fossil record. Herein we describe newly collected specimens from the Molino Alto 1 locality, Teruel Province, Spain, and review previously described materials from the nearby locality of Galve; the sites lie in the same horizon in the upper El Castellar Formation and are of early Barremian age. On this basis, we recognize and name Aliaga molinensis, gen. et sp. nov., and provisionally place in the same genus a previously described species, cf. Aliaga henkeli, comb. nov., which appears to be the largest known spalacotheriid. The two species are characterized by a distinctive, multicuspate cingulid on lower cheek teeth. Based on acuteness of molar cusp triangulation and other features (e.g., planar molar shearing surfaces, elongation and cusp pattern of penultimate premolar, reduction of last molar, simplification of upper molar crown pattern), the species are referred to the Spalacolestinae. This subfamily is most diverse in North America, where it ranged from Albian-Campanian, but first appears in the Barremian of Western Europe, supporting the hypothesis that the group had a Eurasian origin and later dispersed to North America. © 2014 by the Society of Vertebrate Paleontology.
Czaplewski N.J.,Oklahoma Museum of Natural History |
Morgan G.S.,New Mexico Museum of Natural History
PeerJ | Year: 2015
A new species of Apatemyidae, Sinclairella simplicidens, is based on four isolated teeth that were screenwashed from fissure fillings at the late Oligocene Buda locality, Alachua County, Florida. Compared to its only congener Sinclairella dakotensis, the new species is characterized by upper molars with more simplified crowns, with the near absence of labial shelves and stylar cusps except for a strong parastyle on M1, loss of paracrista and paraconule on M2 (paraconule retained but weak on M1), lack of anterior cingulum on M1-M3, straighter centrocristae, smaller hypocone on M1 and M2, larger hypocone on M3, distal edge of M2 continuous from hypocone to postmetacrista supporting a large posterior basin, and with different tooth proportions in which M2 is the smallest rather than the largest molar in the toothrow. The relatively rare and poorly-known family Apatemyidae has a long temporal range in North America from the late Paleocene (early Tiffanian) to early Oligocene (early Arikareean). The new species from Florida significantly extends this temporal range by roughly 5 Ma to the end of the Paleogene near the Oligocene-Miocene boundary (from early Arikareean, Ar1, to late Arikareean, Ar3), and greatly extends the geographic range of the family into eastern North America some 10° of latitude farther south and 20° of longitude farther east (about 2,200 km farther southeast) than previously known. This late occurrence probably represents a retreat of this subtropically adapted family into the Gulf Coastal Plain subtropical province at the end of the Paleogene and perhaps the end of the apatemyid lineage in North America. © 2015 Czaplewski and Morgan.
Cifelli R.L.,Oklahoma Museum of Natural History |
Davis B.M.,Oklahoma Museum of Natural History |
Davis B.M.,University of Louisville
Journal of Vertebrate Paleontology | Year: 2015
We report a diverse assemblage of tribosphenidan mammals from several localities in the Cloverly Formation (Lower Cretaceous, Albian) of Montana and Wyoming. This unit is of historical significance for yielding well-known dinosaurs (e.g., Deinonychus antirrhopus, Tenontosaurus tilletti) and early mammals (e.g., Gobiconodon ostromi, Montanalestes keeblerorum). We provisionally identify 13 taxa (five of which are formally recognized), including Pappotherium pattersoni, a new species of the deltatheroidan Oklatheridium (O. wiblei, sp. nov.), a eutherian (Montanalestes, previously named), and two new basal tribosphenidans (Argaliatherium robustum, gen. et sp. nov., and Carinalestes murensis, gen. et sp. nov.). An unnamed taxon, represented by associated but almost edentulous dentaries, is interpreted to have had four incisors, a single-rooted canine, three premolars, and four molars, indicating that the metatherian tooth formula was established by the Albian. In addition, an indeterminate lower molar fragment preserving twinned talonid cusps and a buccal postcingulid provides the earliest evidence for Marsupialiformes. We also provide a more detailed description of the associated dentaries (holotype) of Montanalestes keeblerorum. The mammalian fauna from the Cloverly Formation shares several taxa with the roughly contemporaneous Trinity Group of Oklahoma and Texas, an observation that also applies to the dinosaur fauna, suggesting some degree of latitudinal homogeneity among described terrestrial vertebrates in this part of the North American Early Cretaceous. © 2015 by the Society of Vertebrate Paleontology.
Joyce W.G.,University of Tubingen |
Petricevic A.,University of Tubingen |
Lyson T.R.,Yale University |
Lyson T.R.,Marmarth Research Foundation |
Czaplewski N.J.,Oklahoma Museum of Natural History
Journal of Paleontology | Year: 2012
A near complete shell from the Hemphillian 4 (Miocene/Pliocene boundary) Buis Ranch local fauna of Beaver County, Oklahoma, represents a fossil box turtle. An anterior contact of neural III and neural V with costal III and costal V only, respectively, presence of a small contact between the suprapygal and eleventh peripherals, development of a thin peripheral lip for articulation with the posterior plastral lobe, placement of the vertebral III/IV sulcus on neural VII, presence of two anterior musk duct glands, a rounded posterior plastral lobe, an elongate shell outline, and a complete neural series diagnose the fossil as a new species, Terrapene parornata n. sp. A phylogenetic analysis of fossil box turtles places T. parornata along the phylogenetic stem of the extant taxon T. ornata. The holotype of 'Terrapene longinsulae' cannot be distinguished from Terrapene ornata and is therefore synonymized. Finally, 'Terrapene' corneri lacks characters of crown group Terrapene and may therefore represent a stem box turtle. The provenance of the holotype of 'Terrapene longinsulae' is more poorly known than previously recognized and this specimen may originate from Kansas or Nebraska and be early Miocene to late Pleistocene in age. Terrapene parornata is therefore the oldest demonstrable representative of crown group Terrapene (ca. 5.34.6 Ma). 'Terrapene' corneri from the late Barstovian of Nebraska and fragmentary material from the middle Barstovian of Nebraska by contrast are the oldest representative of the Terrapene lineage (ca. 14.511.5 Ma). A review of morphological characters related to shell kinesis reveals that most are highly correlated. The results of the phylogenetic analysis converge upon those of molecular data when these correlated characters are omitted from the analysis. © 2012 The Paleontological Society.
Carpenter K.,Utah State University |
Carpenter K.,University of Colorado at Boulder |
Cifelli R.L.,Oklahoma Museum of Natural History
Cretaceous Research | Year: 2016
We describe a small ilium, with fibrous texture characteristic of juvenile bone, from the lower Cenomanian of central Utah, U.S.A. The ilium was recovered from the upper part of the Mussentuchit Member of the Cedar Mountain Formation. The ilium most closely resembles that of immature ceratopsid ilia referred to Agujaceratops mariscalensis from the Campanian Aguja Formation of southern Texas, U.S.A. Both have everted dorsal margins over the iliac body, subhorizontal postacetabular processes, and laterally compressed, anteroventrally curved preacetabular processes. If correctly identified, the small ilium from the Cedar Mountain Formation is the oldest ceratopsid or ceratopsoid known, and shows that the diversity of early ceratopsians was greater than previously realized. © 2015 Elsevier Ltd.