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Litopterns
Litopterna (from "smooth heel") is an extinction, extinct order of South American native ungulates that lived from the Paleocene to the Pleistocene-Holocene around 62.5 million to 12,000 years ago (or possibly as late as 3,500 years ago), and were also present in Antarctica during the Eocene. They represent the second most diverse group of South American ungulates after Notoungulata. It is divided into nine families, with Proterotheriidae and Macraucheniidae being the most diverse and last surviving families. Diversity The body forms of many litopterns, notably in the limb and skull structure, are broadly similar to those of living ungulates, unlike other South American native ungulate groups, which are often strongly divergent from living ungulates. Paleocene and Eocene litopterns generally had small body masses, with ''Protolipterna'' (Protolipternidae) estimated to have had a body mass of , though the Eocene Sparnotheriodontidae, sparnotheriodontids were considerably large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South American Native Ungulate
South American native ungulates, commonly abbreviated as SANUs, are extinct ungulate-like mammals that were indigenous to South America from the Paleocene (from at least 63 million years ago) until the end of the Late Pleistocene (~12,000 years ago). They represented a dominant element of South America's Cenozoic terrestrial mammal fauna prior to the arrival of living ungulate groups in South America during the Pliocene and Pleistocene as part of the Great American Interchange. They comprise five major groups conventionally ranked as Order (biology), orders—Astrapotheria, Litopterna, Notoungulata, Pyrotheria, and Xenungulata—as well as the primitive "condylarth" groups Didolodontidae and Kollpaniinae. It has been proposed that some or all of the members of this group form a clade, named Meridiungulata, though the relationships of South American ungulates remain largely unresolved. The two largest groups of South American ungulates, the notoungulates and the litopterns, were the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrauchenia
''Macrauchenia'' ("long llama", based on the now-invalid llama genus, ''Auchenia'', from Greek "big neck") is an extinct genus of large ungulate native to South America from the Pliocene or Middle Pleistocene to the end of the Late Pleistocene. It is a member of the extinct order Litopterna, a group of South American native ungulates distinct from the two orders which contain all living ungulates which had been present in South America since the early Cenozoic, over 60 million years ago, prior to the arrival of living ungulates in South America around 2.5 million years ago as part of the Great American Interchange. The bodyform of ''Macrauchenia'' has been described as similar to a camel, being one of the largest-known litopterns, with an estimated body mass of around 1 tonne. The genus gives its name to its family, Macraucheniidae, which like ''Macrauchenia'' typically had long necks and three-toed feet, as well as a retracted nasal region, which in ''Macrauchenia'' manifests as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterotheriidae
Proterotheriidae is an extinction, extinct family of Litopterna, litoptern ungulates known from the Eocene-Late Pleistocene of South America. Members of the group were small-medium sized cursorial Herbivore, herbivores with brachydont Tooth, teeth, with their Toe, toes showing progressive reduction, with later members of the group bearing weight on a single large toe similar to living Horse, horses. Description Two subfamilies and 18 genera of Proterotheriidae are known. All forms were small or medium-sized. Typical is a reduction of the number of toes and brachydont or mesodont teeth. The family is recorded since the late Palaeocene. Various fossils are known from many parts of the South American continent. The diversity decreased in the Miocene to Pliocene and it has been assumed for a long time that they entirely disappeared in the late Pliocene. However, fossils found in Argentina, Brazil and Uruguay show that one member of the group, ''Neolicaphrium recens'' survived into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalabrinitherium
''Scalabrinitherium'' is an extinct genus of mammals of the family Macraucheniidae. Fossils of this animal were found among the fossils of prehistoric xenarthrans in the Ituzaingó Formation of Argentina.''Scalabrinitherium'' at .org Description This animal was rather similar to a with a slightly heavy build; the was long and low, the front teeth were slightly spatulate, and the nasal aperture set far back. It is possible tha ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theosodon
''Theosodon'' is an extinct genus of litoptern mammal from the Early to Middle Miocene of South America. Description ''Theosodon'' was long-legged with a long neck resembling modern llamas or guanacos. It was large for a litoptern, reaching up to in length and weighing up to . It had a long neck and tapir-like, three-toed feet, and like other litopterns and modern horses, tapirs and rhinos, it bore its weight on its middle toes. Extraordinarily, rather than having nostrils at the front of its head, ''Theosodon'' had its nostrils on the top of its snout, halfway between the forehead and the tip of the snout, and its nostrils pointed upwards rather than forwards, possibly as an adaptation for browsing on prickly vegetation. History and species ''Theosodon'' has been known since the 19th century, and by 1910 seven species had been described within the genus, all from the early Miocene Santa Cruz Formation in Argentina. The name ''Theosodon'' means "god tooth". The first f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sparnotheriodontidae
Sparnotheriodontidae is an enigmatic extinct family of litopterns known primarily from teeth. Sparnotheriodontids are one of two South American native ungulate clades known to have reached Antarctica, the other being astrapotheres. Description Sparnotheriodontids ranged in size from the mid-sized ''Phoradiadus'' to the large ''Sparnotheriodon''. ''Sparnotheriodon'' and one species of ''Notiolofos'', ''N. arquinotiensis'', have been estimated to have had masses of roughly . Another species of ''Notiolofos'', ''N. regueroi'', was smaller, with a body mass estimated to have been between 25 and 58 kg. Classification The phylogenetic position of Sparnotheriodontidae is uncertain. Most researchers consider them to belong to Litopterna. In contrast, Cifelli and Bergqvist have argued that sparnotheriodontids are condylarths. Their methodology, based on attempting to associate isolated teeth and isolated postcranial bones based on size and relative abundance, has been criticized. Phylo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adianthidae
Adianthidae is an extinct family of litopterns that existed from the Middle Eocene (Mustersan) to the Early Miocene (Santacrucian). Description Adianthids were actively mobile herbivores. They were small in size when compared to most litopterns. Most species did not exceed the size of a cat. Although small in size, the adianthids showed dental features that were already specialized even in the Oligocene genera. The molars were equipped with ridges, and the upper molars were provided with crescent-shaped metacones and paracones, with a columnar parastyle and a very reduced or absent mesostyle. The lower fourth premolar was provided with a crested talonid, and the lower molars were double crescent-shaped or nearly so. The upper fourth premolar was molar-shaped, and the teeth from the third premolar to the upper third molar had three primary dimples and (in the more derived forms) a few accessory dimples behind the prostylar ''cingulum'' in front of the ''cingulum'' of the postipo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adianthus
''Adianthus'' is an extinct genus of litoptern that lived during the Early Miocene to the Middle Miocene in what is now Argentina and Chile. Description This animal is only known from fragmentary remains, mainly from its teeth, and was probably similar to its relative '' Adiantoides''. It was a small animal with generalist teeth, but it had some unusual characteristics. The crown of its teeth was higher than in ''Adiantoides'', and the lower premolars were more molariform. The second lower incisor and the lower canine had three lingually directed ridges, forming two closed basins. The first three premolars had two ridges, while the fourth premolar was completely molariform. Classification ''Adianthus bucatus'' was first described in 1891 by Florentino Ameghino, based on a single tooth of enigmatic shape, perhaps coming from the so-called "''Notohippus'' beds". Subsequently, Ameghino described a mandible with teeth as a new species, ''Adianthus patagonicus''; however, those rema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Didolodontidae
Didolodontidae is a possibly paraphyletic family of "condylarth" mammals known from the Paleogene of South America, with most specimens known from Argentina. They were generally small-medium in body size, and had a bunodont dentition. A close relationship with litopterns has been suggested by some studies. They range in age from the early Paleocene (Selandian/Peligran) to late Eocene (Priabonian/Mustersan The Mustersan age is a period of geologic time (48.0–42.0 Mya (unit), Ma) within the Eocene epoch of the Paleogene, used more specifically within the South American land mammal age (SALMA) classification. It follows the Casamayoran and precedes th ...). The attribution of '' Salladolodus deuterotheroides'' from the Late Oligocene of Bolivia to the family is doubtful. References Paleocene first appearances Eocene extinctions Prehistoric mammal families Condylarths Meridiungulata {{Paleo-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ungulate
Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined to be a polyphyletic and thereby invalid clade based on molecular data. As a result, true ungulates had since been reclassified to the newer clade Euungulata in 2001 within the clade Laurasiatheria while Paenungulata has been reclassified to a distant clade Afrotheria. Living ungulates are divided into two orders: Perissodactyla including Equidae, equines, rhinoceroses, and tapirs; and Artiodactyla including Bos, cattle, antelope, Sus (genus), pigs, giraffes, camels, Ovis, sheep, deer, and Hippopotamidae, hippopotamuses, among others. Cetaceans such as Whale, whales, Dolphin, dolphins, and Porpoise, porpoises are also classified as artiodactyls, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thoatherium
''Thoatherium'' (meaning "active swift-beast") is an extinct genus of litoptern mammals from the Early Miocene of Argentina. Fossils of the genus have been found in the Santa Cruz Formation in Argentina.''Thoatherium'' at .org Description With a length of , the -like ''Thoatherium'' was a small representative of the order . Judging from its long legs, it was a fast runner. ''Thoatherium'' had remarkably reduced toes; ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
