A mastodon is a member of the genus Mammut, which, strictly defined, was endemic to North America and lived from the late Miocene to the early Holocene. Mastodons belong to the order Proboscidea, the same order as elephants and mammoths. Mammut is the type genus of the extinct family Mammutidae, which diverged from the ancestors of modern elephants at least 27-25 million years ago, during the Oligocene.
Camelids are members of the biological family Camelidae, the only currently living family in the suborder Tylopoda. The seven extant members of this group are: dromedary camels, Bactrian camels, wild Bactrian camels, llamas, alpacas, vicuñas, and guanacos. Camelids are even-toed ungulates classified in the order Artiodactyla, along with species including whales, pigs, deer, cattle, and antelopes.
Lama is a genus containing the extant South American camelids: the wild guanaco and vicuña and the domesticated llama, alpaca, and chilihueque. Before the Spanish conquest of the Americas, llamas, alpacas, and chilihueques were the only domesticated ungulates of the continent. They were kept not only for their value as beasts of burden, but also for their flesh, hides, and wool.
Gomphotheres are an extinct group of proboscideans related to modern elephants. They were widespread across Africa Eurasia and North America during the Miocene and Pliocene epochs and dispersed into South America during the Pleistocene as part of the Great American Interchange. Gomphotheres are a paraphyletic group that is ancestral to Elephantidae, which contains modern elephants, as well as Stegodontidae. While most famous forms such as Gomphotherium had long lower jaws with tusks, which is the ancestral condition for the group, some later members developed shortened (brevirostrine) lower jaws with either vestigial or no lower tusks, looking very similar to modern elephants, an example of parallel evolution, which outlasted the long-jawed gomphotheres. By the end of the Early Pleistocene, gomphotheres became extinct in Afro-Eurasia, with the last two genera, Cuvieronius ranging from southern North America to western South America, and Notiomastodon having a wide range over most of South America until the end of the Pleistocene around 12,000 years ago, when they became extinct following the arrival of humans.
Carnassials are paired upper and lower teeth modified in such a way as to allow enlarged and often self-sharpening edges to pass by each other in a shearing manner. This adaptation is found in carnivorans, where the carnassials are the modified fourth upper premolar and the first lower molar. These teeth are also referred to as sectorial teeth.
Chasmaporthetes, also known as hunting or running hyena, is an extinct genus of hyenas distributed in Eurasia, North America, and Africa during the Pliocene-Pleistocene epochs, living from 4.9 million to 780,000 years ago, existing for about 4.12 million years. The genus probably arose from Eurasian Miocene hyenas such as Thalassictis or Lycyaena, with C. borissiaki being the oldest known representative. The species C. ossifragus was the only hyena to cross the Bering land bridge into the Americas, and ranged over what is now Arizona and Mexico during Blancan and early Irvingtonian Land Mammal ages, between 5.0 and 1.5 million years ago.
Poebrotherium is an extinct genus of camelid, endemic to North America. They lived from the Eocene to Miocene epochs, 46.3—13.6 mya, existing for approximately 32 million years.
Oxyaena is an extinct genus of placental mammals from extinct subfamily Oxyaeninae within extinct family Oxyaenidae, that lived in Europe, Asia and North America during the early Eocene.
Nothrotheriops is a genus of Pleistocene ground sloth found in North America, from what is now central Mexico to the southern United States. This genus of bear-sized xenarthran was related to the much larger, and far more famous Megatherium, although it has recently been placed in a different family, Nothrotheriidae. The best known species, N. shastensis, is also called the Shasta ground sloth.
Herpetotherium is an extinct genus of metatherian mammal, belonging to the possibly paraphyletic family Herpetotheriidae. Native to North America from the Eocene to Early Miocene, fossils have been found in California, Oregon, Texas, Florida, Montana, Wyoming, Colorado, North and South Dakota, Nebraska, and Saskatchewan. The oldest species, H. knighti, is dated to around 50.3 mya, and the most recent, an unnamed species, may be as recent as 15.97 mya. A morphological analysis of marsupials and basal metatherians conducted in 2007 found Herpetotherium to be the sister group to extant marsupials. It is the youngest known metatherian from North America until the migration of the Virginia opossum from South America within the last 2 million years.
Mount Blanco is a small white hill — an erosional remnant — located on the eastern border of the Llano Estacado within Blanco Canyon in Crosby County, Texas. With Blanco Canyon, it is the type locality of the early Pleistocene Blanco Formation of Texas and Kansas, as well as the Blancan fauna, which occurs throughout North America. Mount Blanco is a Late Blancan age site, and is associated with other Late Blancan sites from Texas such as Red Light and Hudspeth local faunas from Hudspeth County, and the Cita Canyon fauna from Randall County.
Archaeohippus is an extinct three toed member of the family Equidae known from fossils of early Oligocene to middle Miocene age. The genus is noted for several distinct skeletal features. The skull possesses deeply pocketed fossa in a notably long preorbital region. The genus is considered an example of phyletic dwarfism with adults estimated at being on average 20 kilograms in weight. This is in contrast to the most common equid of the period, Miohippus. Characters of the teeth show a mix of both primitive and advanced traits. The advanced traits are very similar to those shown in the genus Parahippus. The noted similarities of Archaeohippus and Parahippus show them to be descended from a common ancestor. They are considered sister species.
Paracamelus is an extinct genus of camel in the family Camelidae. It originated in North America and crossed the Beringian land bridge into Eurasia during the Late Miocene, about 6 million years ago (Ma). It is the presumed ancestor to living camels of the genus Camelus.
Pleiolama is an extinct genus of terrestrial herbivore in the family Camelidae, endemic to North America during the Pliocene.
Palaeolama is an extinct genus of laminoid camelids that existed from the Late Pliocene to the Early Holocene. Their range extended from North America to the intertropical region of South America.
The Polk County paleontological sites are assemblages of Early Miocene to Late Pleistocene vertebrates occurring in Polk County, Florida, United States.
Neolicaphrium is an extinct genus of ungulate mammal belonging to the extinct order Litopterna. This animal lived from the Late Pliocene (Chapadmalalan) to the Late Pleistocene (Lujanian) in southern South America, being the last survivor of the family Proterotheriidae.
Gypsonictops is an extinct genus of leptictidan mammals of the family Gypsonictopidae, which was described in 1927 by George Gaylord Simpson. Species in this genus were small mammals and the first representatives of the order Leptictida, that appeared during the Upper Cretaceous.
Paedotherium is an extinct, potentially paraphyletic genus of Notoungulate, belonging to the family Hegetotheriidae, composed of small-sized, rodent or lagomorph-like South American ungulates. Four species are unambiguously recognized, from the Late Miocene to the Pleistocene of Argentina, and from the late Miocene of Bolivia and Chile.
Ernestokokenia is an extinct genus of mammal, belonging to the Didolodontidae. It lived during the Early Eocene and the Middle Eocene, and its fossils were discovered in South America.
