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Gnatusuchus
''Gnatusuchus'' is an extinct genus of caiman represented by the type species ''Gnatusuchus pebasensis'' from the Middle Miocene Pebas Formation of Peru. ''Gnatusuchus'' lived about 13 million years ago (Ma) in a large wetland system called the Pebas mega-wetlands that covered over one million square kilometers of what is now the Amazon Basin (the modern basin had not yet developed at that time and instead of draining from west to east into the Atlantic Ocean, river systems drained northward through the wetlands and into the Caribbean Sea). Discovery and naming Fish and molluscs have long been known from the Pebas Formation, however starting in 2002 systematic surveys of the Peruvian Iquitos area have led to the discovery of many vertebrate remains including further fish remains, mammals, turtles and an abundance of crocodilians, with two contemporaneous lignitic bonebeds preserving a minimum of 7 coexisting taxa. Among the fossils recovered from the Iquitos localities is the holo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnatusuchus Size
''Gnatusuchus'' is an extinct genus of caiman represented by the type species ''Gnatusuchus pebasensis'' from the Middle Miocene Pebas Formation of Peru. ''Gnatusuchus'' lived about 13 million years ago (Ma) in a large wetland system called the Pebas mega-wetlands that covered over one million square kilometers of what is now the Amazon Basin (the modern basin had not yet developed at that time and instead of draining from west to east into the Atlantic Ocean, river systems drained northward through the wetlands and into the Caribbean Sea). Discovery and naming Fish and molluscs have long been known from the Pebas Formation, however starting in 2002 systematic surveys of the Peruvian Iquitos area have led to the discovery of many vertebrate remains including further fish remains, mammals, turtles and an abundance of crocodilians, with two contemporaneous lignitic bonebeds preserving a minimum of 7 coexisting taxa. Among the fossils recovered from the Iquitos localities is the holo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globidentosuchus
''Globidentosuchus'' is an extinct genus of basal caimanine crocodylian known from the late Middle to Late Miocene of the Middle and the Upper Members of the Urumaco Formation at Urumaco, Venezuela. Its skull was very short and robust, with large units of spherical teeth used to break the shells of molluscs as part of its durophagus diet. It is thought to be one of the most basal Caimanines, even sharing some traits with alligatorids. Etymology The generic name ''Globidentosuchus'' is derived from the Latin roots ''globus'' meaning "sphere" and ''dens'' meaning "tooth", referring to the spherical teeth in the posterior skull, and Greek ''souchos'' meaning "crocodile" after its classification. The species name ''brachyrostris'' is derived from the Greek ''brachys'' meaning "short" and Latin ''rostrum'' meaning "snout" after the truncated and robust rostrum of the species. History and taxonomy ''Globidentosuchus'' was described in 2013 by T. M. Scheyer and colleagues, the ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pebas Formation
The Pebas Formation is a lithostratigraphic unit of Miocene age, found in western Amazonia. The formation extends over , including parts of Brazil, Peru, Ecuador and Colombia.Wesselingh et al., 2006 It is interpreted as representing the deposits of a lake ("Lake Pebas") or series of lakes, formed within the foreland basin of the Andes mountain belt. It is known for its abundant fossil ostracods and molluscs and an unusually diverse group of crocodylians.Sala Gismondi et al., 2006 Fossil content Correlations Laventan Huayquerian References Bibliography * * * Further reading * {{cite LSA , first=P. , last=Antoine , first2=J.A. , last2=Abello , first3=S. , last3=Adnet , first4=A.J. , last4=Altamirano Sierra , first5=P. , last5=Baby , first6=G. , last6=Billet , first7=M. , last7=Boivin , first8=Y. , last8=Calderón , last9=Candela and J. Chabain, F. Corfu, D. A. Croft, M. Ganerød, C. Jaramillo, S. Klaus, L. Marivaux, R. E. Navarrete, M. J. Orliac, F. Par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laventan
The Laventan ( es, Laventense) age is a period of geologic time (13.8 to 11.8 Ma) within the Middle Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Colloncuran and precedes the Mayoan age.Madden et al., 1997 Etymology The age is named after the Miocene Lagerstätte La Venta, where a rich biodiversity from the Middle Miocene has been recovered from the Honda Group. Formations Fossil content Correlations The Laventan (13.8 to 11.8 Ma) correlates with: * NALMA ** latest Barstovian (15.97-13.65 Ma)Barstovian at Fossilworks.org ** early |
Caiman
A caiman (also cayman as a variant spelling) is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family, the other being alligators. Caimans inhabit Mexico, Central and South America from marshes and swamps to mangrove rivers and lakes. They have scaly skin and live a fairly nocturnal existence. They are relatively small-sized crocodilians with an average maximum weight of depending on species, with the exception of the black caiman (''Melanosuchus niger''), which can grow more than in length and weigh in excess of 1,000 kg (2,200 Ib). The black caiman is the largest caiman species in the world and is found in the slow-moving rivers and lakes that surround the Amazon basin. The smallest species is the Cuvier's dwarf caiman (''Paleosuchus palpebrosus''), which grows to long. There are six different species of caiman found throughout the watery jungle habitats of Central and Southern America. The average length for most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachychampsa
''Brachychampsa'' is an extinct genus of alligatoroid, possibly a basal caiman. Specimens have been reported from New Mexico, Colorado, Wyoming, Montana, North and South Dakota, New Jersey, and Saskatchewan, though only those from Montana, Utah, and New Mexico are based on material sufficient to justify the referral. One specimen has been reported from the Darbasa Formation of Kazakhstan, although the species status is indeterminate for the fossil. The genus first appeared during the late Campanian stage of the Late Cretaceous (Judithian North American stage) and became extinct during the late Maastrichtian stage of the Cretaceous (Lancian North American Land Mammal "Age"). ''Brachychampsa'' is distinguished by an enlarged fifth maxillary tooth in the upper jaw. Species The type species of ''Brachychampsa'' is ''B. montana'', first discovered from the Hell Creek Formation of Montana and described by Charles W. Gilmore in a paper in 1911. In that same paper, Gilmore recombine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caimaninae
A caiman (also cayman as a variant spelling) is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family, the other being alligators. Caimans inhabit Mexico, Central and South America from marshes and swamps to mangrove rivers and lakes. They have scaly skin and live a fairly nocturnal existence. They are relatively small-sized crocodilians with an average maximum weight of depending on species, with the exception of the black caiman (''Melanosuchus niger''), which can grow more than in length and weigh in excess of 1,000 kg (2,200 Ib). The black caiman is the largest caiman species in the world and is found in the slow-moving rivers and lakes that surround the Amazon basin. The smallest species is the Cuvier's dwarf caiman (''Paleosuchus palpebrosus''), which grows to long. There are six different species of caiman found throughout the watery jungle habitats of Central and Southern America. The average length for most o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stangerochampsa
''Stangerochampsa'' is an extinct genus of globidontan alligatoroid, possibly an alligatorine or a stem-caiman, from the Late Cretaceous of Alberta. It is based on RTMP.86.61.1, a skull, partial lower jaws, and partial postcranial skeleton discovered in the late Campanian–early Maastrichtian-age Horseshoe Canyon Formation. ''Stangerochampsa'' was described in 1996 by Wu and colleagues. The type species is ''S. mccabei''. The generic name honors the Stanger family, the owners of the ranch where the specimen was found, and the species name honors James Ross McCabe, who discovered, collected, and prepared it. ''Stangerochampsa'' is described as "small to medium–sized"; the type skull is long from the tip of the snout to the occipital condyle, and is wide at its greatest, while the thigh bone is long. It had heterodont dentition, with large crushing teeth at the rear of the jaws. Classification Wu and colleagues, using phylogenetic analyses, found their new genus to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligatorinae
Alligatorinae is a subfamily within the family Alligatoridae that contains the alligators and their closest extinct relatives, and is the sister taxon to Caimaninae (the caimans). Many genera in Alligatorinae are described, but only the genus ''Alligator'' is still living, with the remaining genera extinct. 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 likely descended from a lineage that crossed the Bering land bridge during the Neogene. The modern American alligator is well represented in the fossil record of the Pleistocene. The alligator's full mitochondrial genome was sequenced in the 1990s. The full genome, published in 2014, suggests that the alligator evolved much more slowly than mammals and birds. Phylogeny Alligatorinae is cladistically defined as ''Alligator mississippiensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globidonta
Globidonta is a clade of alligatoroids that includes alligators, caimans, and closely related extinct forms. It is defined as a stem-based clade including ''Alligator mississippiensis'' (the American Alligator) and all forms more closely related to it than to ''Diplocynodon''. The group's fossil range extends back into the Late Cretaceous with early alligatoroids such as '' Albertochampsa'' and '' Brachychampsa''. Extinct globidontans were particularly common in North America and Eurasia, and their modern range also includes South America. Basal globidontans are characterized by their blunt snouts and bulbous teeth. Modern globidontans have flattened snouts and more conical teeth, and are seen as more generalized than earlier globidontans. Generalized forms are usually expected to be ancestral to more specialized forms rather than descendants of them, so it is unusual for basal members of the group to appear specialized. This seems to conflict with the "Law of the Unspecialized ... [...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] |
Albertochampsa
''Albertochampsa'' is an extinct genus of globidontan alligatoroid (possibly a stem-caiman) from the Late Cretaceous of Alberta. It was named in 1972 by Bruce Erickson, and the type species is ''A. langstoni''. It is known from a skull from the Campanian-age Dinosaur Park Formation, where it was rare; ''Leidyosuchus ''Leidyosuchus'' (meaning " Leidy's crocodile") is an extinct genus of alligatoroid from the Late Cretaceous of Alberta. It was named in 1907 by Lawrence Lambe, and the type species is ''L. canadensis''. It is known from a number of specimens fro ...'' is the most commonly found crocodilian at the Park. The skull of ''Albertochampsa'' was only about 21 cm long (8.3 in). References Crocodilians Late Cretaceous crocodylomorphs of North America Late Cretaceous reptiles of North America Fossil taxa described in 1972 Prehistoric pseudosuchian genera {{Cretaceous-reptile-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
