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Brachyuranochampsa
''Brachyuranochampsa'' is an extinct genus of crocodilian. The only robust occurrence of ''Brachyuranochampsa'' is ''B. eversolei'' from the Middle Eocene of Wyoming.Zangerl, R. (1944). ''Brachyuranochampsa eversolei'', gen. et sp. nov., a new crocodilian from the Washakie beds of Wyoming. ''Annals of Carnegie Museum'', 30:77-84 Another species, ''B. zangerli'' from the lower Bridger Formation at Grizzly Buttes, has been synonymized with another primitive crocodilian, '' "Crocodylus" affinis'', also known from the Bridger Formation. Phylogenetic studies have consistently recovered ''Brachyuranochampsa'' as more basal than the crown group Crocodylidae, which consists of all extant (living) crocodiles. The below cladogram from a 2018 study combining morphological data and molecular DNA evidence shows the placement of ''Brachyuranochampsa'' within Crocodylia. References External links ''Brachyuranochampsa''in the Paleobiology Database The Paleobiology Database is an onli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
"Crocodylus" Affinis
''"Crocodylus" affinis'' is an extinct species of crocodyloid from the Eocene of Wyoming. Fossils were first described from the Bridger Formation by American paleontologist Othniel Charles Marsh in 1871. Marsh described the species, along with every other species of crocodyloid in the Bridger Formation, under the genus ''Crocodylus''. The known specimen of "Crocodylus" affinis is a skull found at Grizzly Buttes, Wyoming, measuring 13 inches in length on the upper surface.Marsh, O. C. (1871). Notice of some new fossil reptiles from the Cretaceous and Tertiary formations. American Journal of Science, s3-1(6), 447–459. doi:10.2475/ajs.s3-1.6.447 Recent phylogenetic studies of crocodyloids show that ''"C." affinis'' is not a species of ''Crocodylus'', but a genus has not yet been erected to include the species. Other Bridger species such as ''Crocodylus clavis'' and ''Brachyuranochampsa zangerli'' have been synonymized with ''"C." affinis''. A 2018 tip dating study by Lee & Yates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prodiplocynodon
''Prodiplocynodon'' is an extinct genus of basal crocodyloid crocodylian. It is one of the only crocodyloids known from the Cretaceous and existed during the Maastrichtian stage. The only species of ''Prodiplocynodon'' is the type species ''P. langi'' from the Lance Formation of Wyoming, known only from a single holotype skull lacking the lower jaw. The skull was collected by the American Museum Expedition of 1892 from exposures near the Cheyenne River in Niobrara County. It was described by Charles C. Mook of the American Museum of Natural History in 1941. The generic name means "before ''Diplocynodon''" because Mook saw close similarities between the holotype skull and that of the alligatoroid ''Diplocynodon'' from the Eocene of Europe. Description Most of the cranial sutures that outline individual bones of the skull are not visible in the holotype, and are often obscured by cracks. However, the overall shape of ''Prodiplocynodon'' is similar to that of basal alligatoroids. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodylus Depressifrons
''Asiatosuchus'' is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to ''Asiatosuchus'' since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus ''Asiatosuchus'' is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of ''Asiatosuchus'', ''A. grangeri'' from the Eocene of Mongolia, belongs in the genus. Most species are now regarded as '' nomina dubia'' or "dubious names", meaning that their type specimens lack the unique anatomical features necessary to justify their classification as distinct species. Other species such as ''"A." germa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asiatosuchus Germanicus
''Asiatosuchus'' is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to ''Asiatosuchus'' since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus ''Asiatosuchus'' is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of ''Asiatosuchus'', ''A. grangeri'' from the Eocene of Mongolia, belongs in the genus. Most species are now regarded as '' nomina dubia'' or "dubious names", meaning that their type specimens lack the unique anatomical features necessary to justify their classification as distinct species. Other species such as ''"A." germa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodylia
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 of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mekosuchinae
Mekosuchinae is an extinct clade of crocodilians from the Cenozoic of Australasia. They first appear in the fossil record in the Eocene in Australia, and survived until the arrival of humans: in the Pleistocene in Australia and within the Holocene in the Pacific islands of Fiji, New Caledonia and Vanuatu. Mekosuchine crocodiles are a diverse group. One of the last species, ''Mekosuchus inexpectatus'' from Holocene New Caledonia, may have been arboreal. The early Miocene species '' Harpacochampsa camfieldensis'' may have resembled a false gharial. Another mekosuchine fossil, currently undescribed, has been found in Miocene deposits from New Zealand. One genus, ''Mekosuchus'', managed to spread to the islands of the Pacific; it is believed to have island-hopped across the Coral Sea, moving first to a now submerged island known as Greater Chesterfield Island, then New Caledonia and onwards. In the Pleistocene, ''Quinkana'' was one of the top terrestrial predators of the Australian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
"Crocodylus" Acer
''"Crocodylus" acer'' is an extinct species of crocodyloid from the Eocene of Utah. A single well preserved skull was described by paleontologist Edward Drinker Cope in 1882 and remains the only known fossil of the species. It was found from the Wasatchian-age Green River Formation. ''"C." acer'' had a long, narrow snout and a low, flattened skull. Some postcranial bones have been attributed to ''"C." acer'' but they have more recently been suggested to belong to the related species '' "C." affinis''. Although they were first placed in the genus ''Crocodylus'', ''"C." acer'' and ''"C." affinis'' are not crocodiles. Recent studies place them as early members of Crocodyloidea, only distantly related to ''Crocodylus''. Although it represents a distinct genus, a generic name has not yet been proposed for ''"C." acer''. A 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data established the inter-rela ... [...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] |
Bridger Formation
The Bridger Formation is a geologic formation in southwestern Wyoming. It preserves fossils dating back to the Ypresian Epoch of the Paleogene Period. The formation was named by American geologist Ferdinand Vandeveer Hayden for Fort Bridger, which had itself been named for mountain man Jim Bridger. The Bridger Wilderness covers much of the Bridger Formation's area. History Before colonization, the lands making up the Bridger Formation had been inhabited by the Apsáalooke, Bannock, Eastern Shoshone, Hinono'eino, Očhéthi Šakówiŋ, Só'taeo'o, Tsétsêhéstâhese, and Ute nations. European settlers began to settle the area around the Bridger Formation in the 19th century, beginning with the establishment of the Oregon Trail in 1830. Fort Bridger – for which the formation would later be named – was established in 1843 by Jim Bridger and Louis Vasquez. In 1868, the remaining Indigenous communities in the area were displaced by the Treaty of Fort Bridger, removing t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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