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Notioprogonia
Notioprogonia is a suborder of the extinction, extinct mammalian order Notoungulata and includes two families, Henricosborniidae and Notostylopidae. Notioprogonia includes the most primitive notoungulates and has argued that Notioprogonia is paraphyletic because it would include the ancestors of the remaining suborders. Notioprogonia is not a natural group but an assemblage of primitive notoungulates; the two families assigned here simply do not clearly belong to any other clades. Description Henricosborniidae, Henricosborniids such as ''Henricosbornia'' and ''Othnielmarshia'' from the late Paleocene (Itaboraian-Casamayoran South American Land Mammal Age, SALMA) have generalized, low-crowned teeth with the dental formula and are dentally the most primitive notoungulates, most likely located near the origin of all other notoungulates. ''Simpsonotus'', also from the late Paleocene and geologically the oldest notoungulate, provides us with the only known Henricoborniid skull. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Paleocene
The Thanetian is, in the International Commission on Stratigraphy, ICS Geologic timescale, the latest age (geology), age or uppermost stage (stratigraphy), stratigraphic stage of the Paleocene epoch (geology), Epoch or series (stratigraphy), Series. It spans the time between . The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age (part of the Eocene). The Thanetian is sometimes referred to as the Late Paleocene. Stratigraphic definition The Thanetian was established by Switzerland, Swiss geologist Eugène Renevier in 1873. The Thanetian is named after the Thanet Formation, the oldest Cenozoic deposit of the London Basin, which was first identified in the area of Kent (southern England) known as the Isle of Thanet. The base of the Thanetian Stage is laid at the base of magnetic chronozone C26n. The references profile (Global Boundary Stratotype Section and Point) is in the Zumaia section (43° 18'N, 2° 16'W) at the beach of Itzurun, Pais Vasco, northern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simpsonotus
''Simpsonotus'' is an extinct genus of notoungulate mammals in the family Henricosborniidae from the Middle to Late Paleocene of South America. Fossils of the genus have been found in the Mealla Formation, a fluvial and lacustrine sedimentary unit of the Salta Basin in northwestern Argentina.Sánchez & Marquillas, 2009, p.389Narváez, 2009, p.172 The genus name honors paleontologist George Gaylord Simpson. Description ''Simpsonotus'' had a skull similar to ''Notostylops'', but with a shorter and rounder face. The genus contains two species; the type species ''S. praecursor'',''S. praecursor'' at .org and the double-sized ''S. major'', [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otrhonia
''Otrhonia'' is an extinct genus of notoungulate, belonging to the Notostylopidae family. It lived during the Late Eocene, and its remains were discovered in South America. Description This animal was approximately the size of a modern racoon, and its length may have been around 60–70 centimeters excluding the tail. The skull was 14–15 centimeters long, and the animal may have been close to 10 kilograms. ''Otrhonia'' had a robust and square skull, characterised by its specialized dentition. As well as in some of its relatives, such as ''Notostylops'', there was a noticeable diastema between the anterior teeth and the premolars. In ''Otrhonia'' this diastema was more elongated than in other genera, and the crown of the molars was higher (hypsodont). The first pair of upper incisors were quite large and directed downwards. Classification ''Otrhonia muehlbergi'' was first described in 1901 by Santiago Roth, based on a fossil found in Argentina near the Lago Musters (hence i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edvardotrouessartia
''Edvardotrouessartia'' is an extinct genus of South American placental mammal that lived during the Middle Eocene of Patagonia. It belonged to the family Notostylopidae, and the order Notoungulata. It is among the many genera of South American ungulates that populated America during much of the Cenozoic, without leaving any modern descendants. Etymology ''Edvardotrouessartia'' was named to honor the french zoologist Édouard Louis Trouessart Édouard Louis Trouessart (25 August 1842 – 30 June 1927) was a French zoologist born in Angers. He studied military medicine in Strasbourg, but was forced to leave school due to serious health problems. In 1864 he started work as ''préparateur .... Characteristics ''Edvardotrouessartia'' is the largest known member of the family Notostylopidae. References {{Taxonbar, from=Q98020340 Notoungulates Eocene mammals of South America Paleogene Argentina Fossils of Argentina Fossil taxa described in 1901 Taxa named by Florentin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripantostylops
''Peripantostylops'' is an extinct genus of notoungulate belonging to the family Henricosborniidae that lived during the Eocene in what is now Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th .... Description This animal is mostly known from fossilized molars. Those were low-crowned (brachydont) and bunolophodont. The upper molars had an highly developed crochet unlike other genera of Henricosborniidae. The third molar either doesn't have a metastyle or it is weakly developed. For the lower molars, the hypoconulid is less separated from the hypoconid. The entoconid of the third molar was highly developed as an independent cuspid. Bibliography {{Taxonbar, from=Q98843245 Notoungulates Eocene mammals of South America Paleogene Argentina Fossils of Argentina Fossil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas '' homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to parallel evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctostylopidae
Arctostylopidae is an extinct family of placental mammals from the Late Palaeocene of Eastern Asia and North America. All arctostylopid specimens in North America have been referred to the genus '' Arctostylops''. They are animals of uncertain affinities to other groups and it was believed that they may be related to 'ungulates'. Originally they were considered to be northern relatives of South American notoungulates 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 resemb ..., specifically Notostylopidae. Recently, other palaeontologists have suggested that they might be descendants of Asian gliriforms, and therefore related to rabbits and rodents. This relationship is based upon similarities in the shape of their tarsal (ankle) bones. In particular, arctostylopid tarsals bear a strong re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiadapis
''Plesiadapis'' is one of the oldest known primate-like mammal genera which existed about 58–55 million years ago in North America and Europe. ''Plesiadapis'' means "near-Adapis", which is a reference to the adapiform primate of the Eocene period, ''Adapis''. ''Plesiadapis tricuspidens'', the type specimen, is named after the three cusps present on its upper incisors. Taxonomy The first discovery of ''Plesiadapis'' was made by François Louis Paul Gervaise in 1877, who first discovered ''Plesiadapis tricuspidens'' in France. The type specimen is MNHN Crl-16, and is a left mandibular fragment dated to the early Eocene epoch. This genus probably arose in North America and colonized Europe on a landbridge via Greenland. Thanks to the abundance of the genus and to its rapid evolution, species of ''Plesiadapis'' play an important role in the zonation of Late Paleocene continental sediments and in the correlation of faunas on both sides of the Atlantic. Two remarkable skeletons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
