Equidae is the taxonomic family of horses and related animals, including the extant horses, asses, and zebras, and many other species known only from fossils. The family evolved around 50 million years ago from a small, multi-toed ungulate into larger, single-toed animals. All extant species are in the genus Equus, which originated in North America. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families.
Galeocerdo is a genus of ground shark. Only a single species, G. cuvier, the tiger shark is extant. The earliest fossils date back to the early Eocene epoch, (Ypresian), around 56–47.8 Million years ago. While historically considered a member of the requiem shark family Carcharhinidae, it is currently considered to be the only member of the family Galeocerdonidae. While this genus was historically considered diverse, including 21 extinct species, morphometric analysis conducted in 2021 suggested that the diversity of the genus included only 5 extinct species much lower than previously assumed. The oldest fossils of the extant G. cuvier date to the middle Miocene.
Mesohippus is an extinct genus of early horse. It lived 37 to 32 million years ago in the Early Oligocene. Like many fossil horses, Mesohippus was common in North America. Its shoulder height is estimated at about 60 cm.
Sand sharks, also known as sand tiger sharks, gray nurse sharks or ragged tooth sharks, are mackerel sharks of the family Odontaspididae. They are found worldwide in temperate and tropical waters. The three species are in two genera.
Zapodidae, the jumping mice, is a family of mouse-like rodents in North America and China.
Miacidae is a former paraphyletic family of extinct primitive placental mammals that lived in North America, Europe and Asia during the Paleocene and Eocene epochs, about 65–33.9 million years ago. These mammals were basal to order Carnivora, the crown-group within the Carnivoraformes.
Arctocyon is an extinct genus of ungulate mammals. Arctocyon was a "ground dwelling omnivore", that lived from 61.3-56.8 Ma. Synonyms of Arctocyon include Claenodon, and Neoclaenodon. Arctocyon was likely plantigrade, meaning that it walked with its feet flat on the ground, rather than on its toes.
Latimeriidae is the only extant family of coelacanths, an ancient lineage of lobe-finned fish. It contains two extant species in the genus Latimeria, found in deep waters off the coasts of southern Africa and east-central Indonesia. In addition, several fossil genera are known from the Mesozoic of Europe, the Middle East, and the southeastern United States, dating back to the Triassic.
The evolution of the horse, a mammal of the family Equidae, occurred over a geologic time scale of 50 million years, transforming the small, dog-sized, forest-dwelling Eohippus into the modern horse. Paleozoologists have been able to piece together a more complete outline of the evolutionary lineage of the modern horse than of any other animal. Much of this evolution took place in North America, where horses originated but became extinct about 10,000 years ago, before being reintroduced in the 15th century.
Ganorhynchus is an extinct genus of prehistoric lungfish from the Devonian period. It is only found in Mansfield, Pennsylvania.
Euthynotus is an extinct genus of prehistoric bony fish that lived during the early Toarcian stage of the Early Jurassic epoch. It is generally considered the basalmost pachycormiform.
Chelonoidis is a genus of turtles in the tortoise family erected by Leopold Fitzinger in 1835. They are found in South America and the Galápagos Islands, and formerly had a wide distribution in the West Indies.
Listriodon is an extinct genus of pig-like animals that lived in Eurasia during the Miocene.
Galeocerdo alabamensis is an extinct relative of the modern tiger shark. Nomenclature of this shark has been debated, and recent literature identified it more closely with the Physogaleus genus of prehistoric shark, rather than Galeocerdo. The classification of Physogaleus is known as tiger-like sharks while Galeocerdo refers to tiger sharks. In 2003, P. alabamensis was classified as Galeocerdo. However, in 2019 they were proclaimed to be more morphologically similar to the genus Physogaleus. This definition was based primarily on tooth shape, as the majority of information on P. alabamensis is a result of studying tooth fossils. Distinctions between Physogaleus and Galeocerdo are difficult with extinct sharks from the Oilgocene/Miocene as there is little paleobiological information allowing for hard conclusions.
Boreostemma is an extinct genus of glyptodonts from northern South America. Fossils assigned to the genus were first described as belonging to Asterostemma from southern South America, but have been placed in the new genus Boreostemma by Carlini et al. in 2008. The type species is B. pliocena. Fossils of Boreostemma have been found in the Honda Group of Colombia, in Peru and Venezuela.
Annea is an extinct genus of carpet shark from the middle Jurassic epoch of the Jurassic period. It is currently known by two species. A. carinata is known from the upper Aalenian and lower Bajocian of Germany. A. maubeugei is known from the middle Toarcian of Belgium. Its name honors Dr. P. L. Maubeuge, who studied the Jurassic of Lorraine in which this species was found. This genus appears to exhibit heterodonty.
Azabbaremys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Teberemt Formation of Mali. It was described in 2001, based on a skull that had been recovered in an expedition in 1981. The genus consists solely of the type species Azabbaremys moragjonesi. The genus name is derived from Azabbar, a monster in Tamasheq folk stories. The species is named for Morag Jones, a research student who participated in the discovery of the specimen and died in the expedition. Azabbaremys is most closely related to another Paleocene side-necked turtle, Acleistochelys.
Cockerellites is a genus of extinct temperate bass described from early Eocene-aged fossils found in the Green River Formation of Wyoming. It is characterized by a sunfish-like body and its stout dorsal and anal spines. The type species, C. liops, was originally named as a species of Priscacara by Edward Drinker Cope upon creating the genus in 1877, but P. liops was moved to the newly created genus Cockerellites by D. Jordan and H. Hanibal in 1923. Some authors, such as Whitlock (2010), still consider Cockerellites liops as a species of Priscacara.
Phenacomyini is a tribe of voles in the subfamily Arvicolinae. It contains five species in two genera, all of which are found in North America.
Thanatosdrakon is a genus of quetzalcoatline azhdarchid pterosaur from the Late Cretaceous Plottier Formation of the Neuquén Basin in western Argentina. The genus name is derived from the Greek words thanatos (=death) and drakon (=dragon), while the specific name is a Quechuan word meaning "flying serpent" and refers to the Incan deity Amaru. The type and only species is Thanatosdrakon amaru, known from two specimens consisting of several well-preserved axial and appendicular bones including material previously undescribed in giant azhdarchids. Thanatosdrakon is one of the oldest known members of the Quetzalcoatlinae. T. amaru lived from about 90 to 86 million years ago.
