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Toxodonts
Toxodontia. Retrieved April 2013. is a suborder of the meridiungulate order Notoungulata. Most of the members of the five included families, including the largest notoungulates, share several dental, auditory and tarsal specializations. The group is named after ''Toxodon'', the first example of the group to be discovered by science. Description Isotemnidae, the oldest and most primitive family of toxodonts, were generally large animals with larger canines than other early notoungulates. The family is probably paraphyletic or polyphyletic since only primitive dental features unite the 12 included genera, such as a complete dentition with unreduced canines and no diastemata in the earliest genera. Likewise, they are only weakly linked to other toxodonts by a few dental features, and their primitive cheek tooth pattern can be basal to all notoungulates except notioprogonians. The oldest of the 12 genera in this family is '' Isotemnus'' known from the Riochican- Casamayoran, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mixotoxodon
''Mixotoxodon'' ("mixture ''Toxodon''") is an extinct genus of notoungulate of the family Toxodontidae inhabiting South America, Central America and parts of southern North America during the Pleistocene epoch, from 1,800,000—12,000 years ago.''Mixotoxodon'' at .org Description 
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Isotemnus
''Isotemnus'' is an extinct genus of notoungulate belonging to the family Isotemnidae. It lived from the Late Paleocene to the Middle Eocene of what is now Argentina. Description This genus was smaller than ''Thomashuxleya'' and ''Periphragnis'', and did not exceed 50 kilograms in weight. Its build was comparable to a modern peccary, with a body relatively massive and strong and sturdy legs. Compared to other Eocene notoungulates, like basal Notohippidae and Notostylopidae, ''Isotemnus'' had an humerus whose distal part had a high medial trochlear crest, while the bicipital radial tuberosity was almost unexistant. The astragalus had a broad and low trochlea with a short neck. The calcaneus had rectangular fibular facets, and an unusually thick sustentaculum. Several of the distinctive anatomical leg characteristics of ''Isotemnus'' could be due to its smaller size ; ''Periphragnis'' and ''Thomashuxleya'', while very similar, had different characteristics. Classification '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martinmiguelia
''Martinmiguelia'' is an extinct genus of Notoungulate, belonging to the family Leontiniidae. It lived during the Middle Eocene, and its fossil remains were found in South America. Description This animal is only known from skull and mandible remains, and it probably shared similarities with later and better known leontiniids, such as '' Scarrittia''. It was smaller-sized than those derived genera, approximately the size of a sheep. ''Martinmiguelia'' was characterized by an archaic dental formula, with a complete dentition (three incisors, one canine, four premolars and three molars) and a quasi-absence of diastema, except for small spaces around the small-sized canines. The molars and premolars were low-crowned (brachydont), a primitive condition for leontinnids. The upper incisors were canine-like and possessed labial girdles, and the second upper incisor was larger than the others. Classification ''Martinmiguelia fernandezi'' was first described in 1995, based on fossils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurygenium
''Eurygenium'' is an extinct genus of notoungulate belonging to the family Notohippidae. It lived during the Late Oligocene in what is today South America. Description It was a medium-sized mammal ; the best known species, ''Eurygenium pacegnum'', was approximately 80 centimeters long and weighed 10 kilograms. Its body was relatively compact, with more robust legs than its relatives, such as ''Rhynchippus''; unlike the latter, however, ''Eurygenium'' had tetradactyls forelegs and a third trochanter near the femoral midline. The skull of ''Eurygenium'' was characterized by a short and broad muzzle, with strong and laterally expanded zygomatic arches. The dentition was devoid of diastema. As in all Notohippidae, premolars and molars had a very high crown (hypsodont). The upper premolars lacked an anterolingual cingulum, while the posterolingual cingulum was reduced. The lower incisors cingulum was reduced or absent, while the lower premolars and molars had a dimple at the trigonid- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchippus
''Rhynchippus'' ("Snout Horse") is an extinct genus of notoungulate mammals from the Late Oligocene (Deseadan in the SALMA classification) of South America. The genus was first described by Florentino Ameghino in 1897 and the type species is ''R. equinus'', with lectotype MACN A 52–31. Fossils of ''Rhynchippus'' have been found in the Agua de la Piedra and Sarmiento Formations of Argentina, the Salla and Petaca Formations of Bolivia, the Tremembé Formation of Brazil,''Rhynchippus'' at .org and the Moquegua Formation of |
Eomorphippus
''Eomorphippus'' is an extinct genus of notohippid notoungulate that lived from the Late Eocene to the Early Oligocene in what is today South America. Description This animal was approximately the size of a goat, with a build probably more robust. It had a heavy and sturdy skull, with a relatively short muzzle. The dentition was characterized by high-crowned (hypsodont) incisors, posterior premolars and molars. The teeth didn't have cementum. The upper incisors were slightly protruding forward. The third upper incisor was wider than the other two, while the fourth premolar was more molariform than the other premolars, but devoid of a distinct hypocone. The upper molars had hypocones, with a variable but generally deep fissure separating them from the protocones. The fissure was blocked by the medial projection of a hooked structure. Apart from the permanent major fossa, the other fossae are erased with wear. Classification The genus ''Eomorphippus'' was first described in 1901 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pampatemnus
''Pampatemnus'' is an extinct genus of notoungulate belonging to the family Isotemnidae that lived during the Early to Middle Eocene of what is now Argentina. Etymology The genus name, ''Pampatemnus'', is composed of the prefix ''Pampa-'', the Quechua word for "plain", and the suffix ''-temnus'', from the greek word ''Τεμγυς'', meaning "groove", a suffix commonly used by Florentino Ameghino to name genera of Isotemnidae. Description ''Pampatemnus'' was discovered in outcrops of the Lumbrera Formation, an Eocene geological formation located in the Guachipas Department of the Salta Province. Two species attributed to the genus have been described : ''Pampatemnus infernalis'' and ''Pampatemnus deuterus''. The species name ''infernalis'' was given to honor the Legion Infernal, a gaucho regiment who took an important role in the Spanish American wars of independence The Spanish American wars of independence (25 September 1808 – 29 September 1833; es, Guerras de i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurostylodon
''Pleurostylodon'' is an extinct genus of notoungulate belonging to the family Isotemnidae. It lived during the Middle Eocene, in what is now Argentina. Description This genus is known from numerous remains, mainly cranial, allowing to reconstruct its morphology. It was approximately the size of a sheep, with an appearance evocating a tapir or a boar. ''Pleurostylodon'' had a large skull, widening in the orbital arch area, and narrowing in the posterior area of the muzzle, whose terminal part was enlarged and had small incisors ; there was no diastema after the canines. The muzzle was shorter than in more derived and specialized toxodonts such as ''Adinotherium'', and the occipital area was narrower. Several characteristics of its maxilla, of its teeth and of its unspecialized auditory region evocates '' Homalodotherium''. The third upper incisor was enlarged, and vaguely resembling a canine, while the canine was larger and lanceolate. The premolars and molars had an external e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homalodotheriidae
Homalodotheriidae is an extinct family comprising four genera of notoungulate mammals known from the Late Eocene (Tinguirirican) through Late Miocene (Chasicoan) of Argentina and Chile in South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ....McKenna, Malcolm C., and Bell, Susan K. 1997. ''Classification of Mammals Above the Species Level.'' Columbia University Press, New York, 631 pp. References Toxodonts Eocene mammals Oligocene mammals Miocene mammals of South America Eocene first appearances Miocene extinctions Prehistoric mammal families {{paleo-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scarrittia
''Scarrittia'' is an extinct genus of hoofed mammal of the family Leontiniidae, native to South America during the Late Oligocene epoch (Deseadan in the SALMA classification). Description ''Scarrittia'' was about in body length, and resembled a rhinoceros with a relatively long body and neck. It had three hoofed toes on each foot, and a very short tail. Due to a fused tibia and fibula, ''Scarrittia'' would have been unable to turn its legs sideways. The short skull had 44 poorly specialized teeth. Natural history This was a very successful genus with various known species, such as ''Scarrittia robusta'', ''S. barranquensis'' and ''S. canquelensis'', which lived around 30 million years ago. They lived in moist forest, near the coast, in wetlands, lakes, swamps, etc. and they ate soft vegetation, grasses, fruits and trees. Some species were omnivorous, eating also eggs and small mammals. They were not adapted for running, though their large size meant they had few enemies. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomashuxleya
''Thomashuxleya'' is an extinct genus of notoungulate mammal, named after famous 19th-century biologist Thomas Huxley. Description ''Thomashuxleya'' was about in length and weighted an estimated , with a heavy body and strong limbs.D. Patterson, Bruce (€2012) ''Bones, Clones, and Biomes: The History and Geography of Recent Neotropical Mammals'' p.83 Its large skull had 44 teeth in its jaws, including large canines which may have been used to dig around in earth. It had four toes on each foot, and probably walked somewhat like a modern peccary. It was a relatively generalised animal, not specialised for any particular way of life. There's an almost complete skeleton of this animal in exhibition in the American Museum of Natural History. This skeleton was discovered during the Scarrit expedition to Patagonia, Argentina, that was led by the paleontologist George Gaylord Simpson. Fossils of ''Thomashuxleya'' have been found in the Sarmiento and Casamayor Formations of Argentin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxodontidae
Toxodontidae is an extinct family of notoungulate mammals, known from the Oligocene to the Holocene (11,000 BP) of South America, with one genus, '' Mixotoxodon'', also known from the Pleistocene of Central America and southwestern North America (Texas).E. Lundelius, et al. 2013. The first occurrence of a toxodont (Mammalia, Notoungulata) in the United States. ''Journal of Vertebrate Paleontology'', Vol 33, No 1, pp. 229–23DOI:10.1080/02724634.2012.711405/ref> They somewhat resembled rhinoceroses, and had teeth with high crowns and open roots, suggesting that they often fed on tough pampas grass. However, isotopic analyses have led to the conclusion that the most recent forms were grazing and browsing generalists. Taxonomy The endemic notoungulate and litoptern ungulates of South America have been shown by studies of collagen and mitochondrial DNA sequences to be a sister group to the perissodactyl Odd-toed ungulates, mammals which constitute the taxonomic order Pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
