Miracinonyx is an extinct genus of felids belonging to the subfamily Felinae that was endemic to North America from the Pleistocene epoch and morphologically similar to the modern cheetah, although its apparent similar ecological niches have been considered questionable due to anatomical morphologies of the former that would have crippled any ability to run as fast. The genus was originally known from fragments of skeletons, but nearly complete skeletons have been recovered from Natural Trap Cave in northern Wyoming.
Antilocapra is a genus of the family Antilocapridae, which contains only a single living species, the pronghorn (Antilocapra americana). Another species, the Pacific pronghorn, lived in California during the Late Pleistocene and survived as recently as 12,000 BP. The name means "antelope-goat".
Hayoceros is an extinct genus of the artiodactyl family Antilocapridae, endemic to North America during the Pleistocene epoch, existing for about 1.5 million years.
Comahuesuchus is an extinct genus of notosuchian crocodylomorphs from the late Cretaceous of Argentina. It was described by palaeontologist José Bonaparte in 1991. The type species is C. brachybuccalis from the Santonian Bajo de la Carpa Formation. In 2023 another species, C. bonapartei from the Sierra Barrosa Formation and Portezuelo Formation, was assigned to the genus.
Pseudhipparion is an extinct genus of three-toed horse endemic to North America during the Miocene. They were herding animals whose diet consisted of C3 plants. Fossils found in Georgia and Florida indicate that it was a lightweight horse, weighing up to 90 pounds. In 2005, fossils were unearthed in Oklahoma. Seven species of Pseudhipparion are known from the fossil record which were very small, following the trend of Bergmann's rule.
Cormohipparion is an extinct genus of horse belonging to the tribe Hipparionini that lived in North America during the late Miocene to Pliocene. This ancient species of horse grew up to 3 feet long.
Hassiacosuchus is an extinct genus of small alligatorid from the early Eocene of Germany, found at the Messel pit. It was named in 1935 by K. Weitzel, and the type species is H. haupti. A second species, H. kayi, was named in 1941 by C.C. Mook for material from the Bridgerian of Wyoming, but was reassigned to Procaimanoidea in 1967 by Wassersug and Hecht. Hassiacosuchus may be the same as Allognathosuchus; Christopher Brochu has recommended continuing to use Hassiacosuchus.
The pronghorn is a species of artiodactyl mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American antelope, prong buck, pronghorn antelope and prairie antelope, because it closely resembles the antelopes of the Old World and fills a similar ecological niche due to parallel evolution. It is the only surviving member of the family Antilocapridae.
Cornwallius is an extinct herbivorous marine mammal of the family Desmostylidae. Cornwallius lived along the North American Pacific Coast from the Early Oligocene (Chattian) through the Oligocene and existing for approximately 7.8 million years.
Hemiauchenia is a genus of laminoid camelids that evolved in North America in the Miocene period about 10 million years ago. This genus diversified and moved to South America in the Late Pliocene approximately 3 to 2 million years ago, as part of the Great American Biotic Interchange, giving rise to modern lamines. The genus became extinct at the end of the Pleistocene. The monophyly of the genus has been considered questionable, with phylogenetic analyses finding the genus to paraphyletic or polyphyletic.
Saltenia is an extinct genus of frogs. It was assigned to the family Pipidae by R. L. Carroll in 1988 and again in 2005 by A. M. Báez and T. Harrison. The single described species, Saltenia ibanezi, is thought to have lived in South America in the Late Cretaceous.
Vanastega is an extinct genus of Triassic temnospondyl amphibian in the family Brachyopidae. It is known from the Cynognathus Assemblage Zone in Burgersdorp, South Africa. The genus contains just one species, Vanastega plurimidens, the type species.
Escavadodon is an extinct genus of pangolin-like myrmecophagous placental mammals of extinct monotypic family Escavadodontidae within extinct order Palaeanodonta, that lived in North America during the middle Paleocene. It contains a single species, Escavadodon zygus, recovered from the Nacimiento Formation of New Mexico.
Tupilakosauridae is an extinct family of dvinosaurian temnospondyls. It contains the genera Slaugenhopia, Thabanchuia, Tupilakosaurus, and possibly Kourerpeton. Tupilakosaurs are known from Texas, Greenland, Russia, and France. The earliest tupilakosaur, Slaugenhopia, is Early Permian in age while the latest known tupilakosaurs are Early Triassic in age. Derived tupilakosaurs possess embolomerous centra in their vertebrae, which are diplospondylous. They also have a deep notch in the pterygoid bone of the palate. Tupilakosaurs were aquatic, and used an undulatory mode of swimming much like that of eels.
Christian Alfred Sidor is an American vertebrate paleontologist. He is currently a Professor in the Department of Biology, University of Washington in Seattle, as well as Curator of Vertebrate Paleontology and Associate Director for Research and Collections at the Burke Museum of Natural History and Culture. His research focuses on Permian and Triassic tetrapod evolution, especially on therapsids.
Eurygnathohippus is an extinct genus of hipparionine horse. The majority of known fossils of members of this genus were discovered in Africa, where members of this genus lived during the late Miocene to Pleistocene interval. Fossils of Eurygnathohippus were also reported from the late Pliocene sediments of the Potwar Plateau in Pakistan and the Siwalik Hills in northwest India.
The St. Marys Formation is a geologic formation in Maryland and Virginia, United States. It preserves fossils dating back to the Miocene Epoch of the Neogene period. It is the youngest Miocene formation present in the Calvert Cliffs and is part of the Chesapeake Group.
The Parachucla Formation is a geologic formation in Florida. It preserves fossils dating back to the Paleogene period.
Sphenovipera jimmysjoyi is an extinct species of sphenodontian dated from the Middle Jurassic. If was discovered in the lower part of the La Boca Formation located in Tamaulipas, Mexico. Only the lower jaw of this organism has been discovered and studied. It is possibly the only species of rhynchocephalian yet discovered to show evidence of venom delivery.
Capromeryx was a genus of dwarf pronghorns (Antilocapridae) that originated in North America during the Pliocene about 5 million years ago. The closest living relative and only surviving member of the family is the North American pronghorn.
