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White River Fauna
The White River Fauna are fossil animals found in the White River Badlands of South Dakota, Wyoming, Colorado and Nebraska in the United States including Badlands National Park. The fossils have been found in the White River Formation, Chadron Formation, Brule Formation, and the Arikaree Formation. Animals from the White River Badlands date from the Eocene, Oligocene, the Miocene, and the Pliocene Epochs. List Genera include: See also * :White River Fauna Further reading * Rachel Benton, ''The White River Badlands: Geology and Paleontology'', Indiana University Press 2015 * William Berryman Scott William Berryman Scott (February 12, 1858 – March 29, 1947) was an American vertebrate paleontologist, authority on mammals, and principal author of the White River Oligocene monographs. He was a professor of geology and paleontology at P ..., ''A history of land mammals in the western hemisphere'', MacMillan Publishing Company, 1913 References Paleogene animals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agnotocastor
''Agnotocastor'' is an extinct member of the beaver family Castoridae. Unlike its modern relative, this species took the place of muskrats in the rivers of North America during the Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ... epoch. The earliest species is ''A. galushai'', which is also the first reliable member of the Castoridae.Emry, R. J. 1972A new species of ''Agnotocastor'' (Rodentia, Castoridae) from the early Oligocene of Wyoming.American Museum Novitates, no. 2485. References Prehistoric beavers Eocene rodents Oligocene rodents Prehistoric rodent genera Eocene mammals of Asia Oligocene mammals of Asia Eocene mammals of North America Oligocene mammals of North America {{paleo-rodent-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathornis
''Bathornis'' ("tall bird") is an extinct lineage of birds related to modern day seriemas, that lived in North America about 37–20 million years ago. Like the closely related and also extinct phorusrhacids, it was a flightless predator, occupying predatory niches in environments classically considered to be dominated by mammals. It was a highly diverse and successful genus, spanning a large number of species that occurred from the Priabonian Eocene to the Burdigalian Miocene epochs. Description Though most material is highly incomplete, ''Bathornis'' is nonetheless known from a variety of skeletal elements: hindlimbs (most commonly tarso-metatarsals), forelimb elements (especially humeri), pelvises and skulls.Federico L. Agnolin (2009)"Sistemática y Filogenia de las Aves Fororracoideas (Gruiformes, Cariamae)"(PDF). Fundación de Historia Natural Felix de Azara: 1–79. ''Bathornis grallator'' is known from a mostly complete skeleton, including the skull, bearing a proportional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entelodont
Entelodontidae, the entelodonts, are an extinct family of pig-like artiodactyls (even-toed ungulates) which inhabited the Northern Hemisphere (Asia, Europe, and North America) from the late Eocene to the Middle Miocene epochs, about 38-19 million years ago. Their large heads, low snouts, narrow gait, and proposed omnivorous diet inspires comparisons to suids (true pigs) and tayassuids (peccaries), and historically they have been considered closely related to these families purely on a morphological basis. However, studies which combine morphological and molecular (genetic) data on artiodactyls instead suggest that entelodonts are cetancodontamorphs, more closely related to hippos and cetaceans than to pigs or other ungulates. Description Entelodonts could get quite large, and in many cases are the largest mammals in their respective ecosystems. The largest entelodont known from a complete skeleton was ''Daeodon'', a North American entelodont which could reach an estimated we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeotherium
''Archaeotherium'' ( grc, αρχαιοθήριον, meaning "ancient beast") is an extinct genus of entelodont artiodactyl endemic to North America during the Eocene and Oligocene epochs (35—28 mya), existing for approximately . ''Archaeotherium'' fossils are most common in the White River Formation of the Great Plains, but it has also been found in the John Day Basin of Oregon and the Trans-Pecos area of Texas. Taxonomy ''Archaeotherium'' was named by Joseph Leidy (1850Its type is ''Archaeotherium mortoni''. It was synonymized subjectively with ''Entelodon'' by Leidy (1853) and synonymized subjectively with ''Elotherium'' by Leidy (1857). It was assigned to Entelodontidae by Leidy (1850), Peterson (1909), Scott (1940), Galbreath (1953), Russell (1980), Carroll (1988) and Effinger (1998). ''Archaeotherium'', along with all other Entelodontidae, is an artiodactyl whose exact taxonomic position has been disputed, but taxonomists agree the group lies between the Suina (pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeocyon Head Restoration
''Archaeocyon'' ("ancient dog") is an extinct genus of the Borophaginae subfamily of canids native to North America. It lived during the Oligocene epoch 32-24 Ma., existing for approximately . Species of ''Archaeocyon'' are among the earliest known borophagines, although a species of ''Otarocyon'' has a slightly earlier first appearance. Fossils have been found across the northern Great Plains and along the west coast of North America. ''Archaeocyon'' was a comparatively small and unspecialized dog. Its dentition (teeth) suggests a slightly more hypocarnivorous (omnivorous) diet than the otherwise similar ''Hesperocyon''. The skeleton is also generalized, lacking specializations for running and retaining a plantigrade foot posture. A few derived features of the dentition support a relationship to Borophaginae and Caninae (the subfamily that includes living canids), rather than to the basal canid subfamily Hesperocyoninae. The temporal position of ''Archaeocyon'' suggests an af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borophaginae
The extinct Borophaginae form one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Hesperocyoninae and extant Caninae. Borophaginae, called "bone-crushing dogs", were endemic to North America during the Oligocene to Pliocene and lived roughly 34—2.5 million years ago, existing for about . Origin The Borophaginae descended from the subfamily Hesperocyoninae. The earliest and most primitive borophagine is the genus ''Archaeocyon'', which is a small fox-sized animal mostly found in the fossil beds in western North America. The borophagines soon diversified into several major groups. They evolved to become considerably larger than their predecessors, and filled a wide range of niches in late Cenozoic North America, from small omnivores to powerful, bear-sized carnivores, such as ''Epicyon''. Species There are 66 identified borophagine species, including 18 new ones that range from the Orellan to Blancan ages. A phylogenetic anal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeocyon
''Archaeocyon'' ("ancient dog") is an extinct genus of the Borophaginae subfamily of canids native to North America. It lived during the Oligocene epoch 32-24 Ma., existing for approximately . Species of ''Archaeocyon'' are among the earliest known borophagines, although a species of ''Otarocyon'' has a slightly earlier first appearance. Fossils have been found across the northern Great Plains and along the west coast of North America. ''Archaeocyon'' was a comparatively small and unspecialized dog. Its dentition (teeth) suggests a slightly more hypocarnivorous (omnivorous) diet than the otherwise similar ''Hesperocyon''. The skeleton is also generalized, lacking specializations for running and retaining a plantigrade foot posture. A few derived features of the dentition support a relationship to Borophaginae and Caninae (the subfamily that includes living canids), rather than to the basal canid subfamily Hesperocyoninae. The temporal position of ''Archaeocyon'' suggests an af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Prenasalis (specimen AMNH 4994) -20120521-RM-224539
''Alligator prenasalis'' is an extinct species of alligator from the Late Eocene period. It is well known, with many fossils having been collected from the Chadron and Brule Formations in South Dakota. The species was first named in 1904, but was originally classified as a crocodile in the genus ''Crocodilus''. It was reassigned to the genus ''Alligator'' in 1918 on the basis of more complete material. It is the earliest known member of the genus ''Alligator''. Taxonomy Junior synonyms Several species of extinct alligatorines have been considered junior synonyms of ''A. prenasalis''. These include ''Caimanoidea visheri'', named by paleontologist Maurice Mehl in 1916 from fragmentary material, and ''Allognathosuchus riggsi'', named in 1931 from a single piece of a lower jaw. Both were considered synonymous with the species in 1972 by paleontologist D.W. Higgins. Mehl used two alternate spellings of ''Caimanoidea'' in his 1916 paper: ''Caimanoideus'' and ''Caimanoeda''. Because t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodilia
Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period ( Cenomanian stage) and are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria. Members of the order's total group, the clade Pseudosuchia, appeared about 250 million years ago in the Early Triassic period, and diversified during the Mesozoic era. The order Crocodilia includes the true crocodiles (family Crocodylidae), the alligators and caimans (family Alligatoridae), and the gharial and false gharial (family Gavialidae). Although the term 'crocodiles' is sometimes used to refer to all of these, crocodilians is a less ambiguous vernacular term for members of this group. Large, solidly built, lizard-like reptiles, crocodilians have long flattened snouts, laterally compressed tails, and eyes, ears, and nostrils at the top ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Prenasalis
''Alligator prenasalis'' is an extinct species of alligator from the Late Eocene period. It is well known, with many fossils having been collected from the Chadron and Brule Formations in South Dakota. The species was first named in 1904, but was originally classified as a crocodile in the genus ''Crocodilus''. It was reassigned to the genus ''Alligator'' in 1918 on the basis of more complete material. It is the earliest known member of the genus ''Alligator''. Taxonomy Junior synonyms Several species of extinct alligatorines have been considered junior synonyms of ''A. prenasalis''. These include ''Caimanoidea visheri'', named by paleontologist Maurice Mehl in 1916 from fragmentary material, and ''Allognathosuchus riggsi'', named in 1931 from a single piece of a lower jaw. Both were considered synonymous with the species in 1972 by paleontologist D.W. Higgins. Mehl used two alternate spellings of ''Caimanoidea'' in his 1916 paper: ''Caimanoideus'' and ''Caimanoeda''. Because t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator
An alligator is a large reptile in the Crocodilia order in the genus ''Alligator'' of the family Alligatoridae. The two extant species are the American alligator (''A. mississippiensis'') and the Chinese alligator (''A. sinensis''). Additionally, several extinct species of alligator are known from fossil remains. Alligators first appeared during the Oligocene epoch about 37 million years ago. The name "alligator" is probably an anglicized form of ', the Spanish term for "the lizard", which early Spanish explorers and settlers in Florida called the alligator. Later English spellings of the name included ''allagarta'' and ''alagarto''. Evolution Alligators and caimans split in North America during the early Tertiary or late Cretaceous (about 53 million to about 65 million years ago). The Chinese alligator split from the American alligator about 33 million years ago and probably descended from a lineage that crossed the Bering land bridge during the Neogene. The modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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