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Litopterns
Litopterna (from grc, λῑτή πτέρνα "smooth heel") is an extinct order of fossil hoofed mammals from the Cenozoic era. The order is one of the five great orders of South American ungulates that were endemic to the continent, until the Great American Biotic Interchange brought new ungulate species. Like other endemic South American mammals, their relationship to other mammal groups had long been unclear, but recent genetic and proteomic evidence indicates that their closest living relatives are Perissodactyls (odd-toed ungulates) including horses, rhinoceros, and tapirs, and that litopterns are closely related to notoungulates, another widespread group of South American ungulates. There were two major groups of litopterns: Proterotheriidae and Macraucheniidae. Proterotheriids were medium to large animals that evolved adaptations for fast running, and occupied a variety of niches that elsewhere were filled by animals such as goats and antelopes, mouse deer, and horses. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrauchenia
''Macrauchenia'' ("long llama", based on the now-invalid llama genus, ''Auchenia'', from Greek "big neck") was a large, long-necked and long-limbed, three-toed native South American mammal in the order Litopterna. The genus gives its name to its family, the Macraucheniidae or "robust litopterns". Like other litopterns, it is most closely related to the odd-toed ungulates ( Perissodactyla), from which litopterns diverged approximately 66 million years ago. The oldest fossils in the genus date to the late Miocene, around seven million years ago, and ''M. patachonica'' disappears from the fossil record during the late Pleistocene, around 20,000-10,000 years ago. ''M. patachonica'' is one of the last and best known member of the family and is known primarily from the Luján Formation in Argentina, but is known from localities across southern South America. Another genus of macraucheniid ''Xenorhinotherium'' was present in northeast Brazil and Venezuela during the Late Pleistocene. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great American Interchange
The Great American Biotic Interchange (commonly abbreviated as GABI), also known as the Great American Interchange and the Great American Faunal Interchange, was an important late Cenozoic paleozoogeographic biotic interchange event in which land and freshwater fauna migrated from North America via Central America to South America and vice versa, as the volcanic Isthmus of Panama rose up from the sea floor and bridged the formerly separated continents. Although earlier dispersals had occurred, probably over water, the migration accelerated dramatically about 2.7 million years ( Ma) ago during the Piacenzian age. It resulted in the joining of the Neotropic (roughly South American) and Nearctic (roughly North American) biogeographic realms definitively to form the Americas. The interchange is visible from observation of both biostratigraphy and nature (neontology). Its most dramatic effect is on the zoogeography of mammals, but it also gave an opportunity for reptiles, amphibia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meridiungulata
South American native ungulates, commonly abbreviated as SANUs, are extinct ungulate-like mammals of controversial affinities that were indigenous to South America prior to the Great American Biotic Interchange. They comprise five major groups conventionally ranked as orders—Astrapotheria, Litopterna, Notoungulata, Pyrotheria, and Xenungulata—as well as some other taxa, such as Didolodontidae and Kollpaniidae. 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 only groups to persist beyond the mid Miocene. Only a few of the largest species of notoungulates and litopterns survived until the end-Pleistocene extinctions. Though most SANUs lived in South America, astrapotheres and litopterns are known from Eocene aged deposits in the Antarctic Peninsu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adianthidae
Adianthidae is an extinct family of Litopterna, litopterns that existed from the Middle Eocene (Mustersan) to the Early Miocene (Santacrucian). Description These Arboreal locomotion, scansorial, Viviparity, viviparous animals were actively mobile and were Herbivore, 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 Cusp (anatomy), metacones and Paracone, paracones, with a columnar parastyle and a very reduced or absent mesostyle. The lower fourth premolar was provided with a crested Molar (tooth), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterotheriidae
Proterotheriidae is an extinction, extinct family of fossil ungulates from the Cenozoic era that displays toe reduction. Despite resembling primitive, small horses, they were only distantly related to them, and instead belonged to the native South American ungulate order Litopterna. 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 the Late Lujanian, Pleistocene. Better known genera of the family include ''Diadiaphorus'' and ''Thoatherium'' from th ... [...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] |
Macraucheniopsis
''Macraucheniopsis'' is an extinct genus of litoptern mammal belonging to the family Macraucheniidae from the Middle to Late Pleistocene of Argentina. It, along with ''Macrauchenia'', ''Neolicaphrium'', and ''Xenorhinotherium'' were among the youngest known genera of litopterns. Classification Cladogram based in the phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ... published by Schmidt ''et al''., 2014, showing the position of ''Macraucheniopsis'': References {{Taxonbar, from=Q113946418 Macraucheniids Pleistocene mammals of South America Pleistocene Argentina Ensenadan Lujanian Fossils of Argentina Fossil taxa described in 1945 Prehistoric placental genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenorhinotherium
''Xenorhinotherium'' is an extinct genus of macraucheniine macraucheniids, closely related to '' Macrauchenia'' of Patagonia. The type species is ''X. bahiense''.''Xenorhinotherium'' at .org Taxonomy Some authors consider the genus ''Xenorhinotherium'' a synonym of ''Macrauchenia'', while all others consider it a distinct genus. The name ''Xenorhinotherium'' means "Strange-Nosed Beast" and ''bahiense'' refers to the Brazilian state of , where the first fossils were found. ''Xenorhinotherium'' wa ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macraucheniidae
Macraucheniidae is a family in the extinct South American ungulate order Litopterna, that resembled various camelids. The reduced nasal bones of their skulls was originally suggested to have housed a small proboscis, similar to that of the saiga antelope. However, one study suggested that they were openings for large moose-like nostrils. Conversely, prehistoric pictographs by indigenous people seems to depict animals interpreted as macraucheniids with trunks. Their hooves were similar to those of rhinoceroses today, with a simple ankle joint and three digits on each foot. Thus, they may have been capable of rapid directional change when running away from predators, such as large phorusrhacid terror birds, sparassodont metatherians, giant short-faced bears ('' Arctotherium)'' and saber-toothed cats (''Smilodon''). Macraucheniids probably lived in large herds to gain protection against these predators, as well as to facilitate finding mates for reproduction. The family Macrauc ... [...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 Fossilworks.org Description 
With a length of , the -like ''Thoatherium'' was a small representative of the order [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notoungulata
Notoungulata is an extinct order of mammalian ungulates that inhabited South America from the early Paleocene to the Holocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms resembling animals as disparate as rabbits and rhinoceroses. Notoungulata are the largest group of South American native ungulates, with over 150 genera in 14 families having been described, divided into two major subgroupings, Typotheria and Toxodontia. Notoungulates first diversified during the Eocene. Their diversity declined during the Late Neogene, with only the large toxodontids persisting until the end of the Pleistocene. Collagen analysis suggests that notoungulates are closely related to litopterns, another group of South American ungulates, and their closest living relatives being perissodactyls (odd-toed ungulates), including rhinoceroses, tapirs and equines. but their relationships to other South American ungulates are uncertain. Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraceratheriidae
Paraceratheriidae is an extinct family of long-limbed, hornless rhinocerotoids, commonly known as paraceratheres or indricotheres, that originated in the Eocene epoch and lived until the early Miocene. The first paraceratheres were only about the size of large dogs, growing progressively larger in the late Eocene and Oligocene. They were most common in the rainforest floodplain region which is now Kazakhstan, India, and southwest China, and lived further inland throughout northern and central Asia as well. The paraceratheres reached the peak of their evolution from the middle Oligocene to the early Miocene, where they became very large, herbivorous mammals. Most genera were about the size of modern draft horses and the extinct giant horse '' Equus giganteus'', with some growing significantly larger. The largest genus was ''Paraceratherium'', which was more than twice as heavy as a bull African elephant, and was one of the largest land mammals that ever lived. However, they remain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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