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Navajosuchus Mooki
''Navajosuchus'' is an extinct genus of alligatorine crocodylian. Its fossils have been found in the Paleocene-age Nacimiento Formation of the San Juan Basin, New Mexico (United States). It was named in 1942 by Charles C. Mook, and the original type species was ''N. novomexicanus''. ''N. novomexicanus'' was based on AMNH 5186, a partial skull collected in 1913. Later research showed that ''Navajosuchus novomexicanus'' was the same as the earlier-named ''Allognathosuchus mooki''. However, ''A. mooki'' does not belong to the genus ''Allognathosuchus'', and so the name of the crocodilian becomes ''Navajosuchus mooki''. Under whichever name is used, this animal would have been a generalized predator of the Nacimiento floodplains. It was the most common Nacimiento Formation crocodilian, found in both the Puercan and Torrejonian faunal assemblages. The precise placement of ''Navajosuchus'' within Alligatoroidea is disputed. Some studies have shown it as a basal member of Alliga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene
The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by Chicxulub impact, an asteroid impact and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. In the Pal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puercan
The Puercan North American Stage on the geologic timescale is the North American faunal stage In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convent ... according to the North American Land Mammal Ages chronology (NALMA), spanning the interval from 66,000,000 to 63,300,000 years Before Present, BP lasting . It is usually considered to be within the Paleocene. The Puercan directly follows the Lancian NALMA, with the K-Pg boundary and K-Pg mass extinction at 66 MYA representing the boundary between the two. The Puercan is followed by the Torrejonian NALMA stage. Puercan age fossils, from the Great Divide Basin, Wyoming, include three newly identified condylarth members of the Periptychidae; ''Miniconus, Miniconus jeanninae, Conacodon, Conacodon hettingeri, Beornus, Beornus honeyi'' Subs ... [...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] |
Crown Group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants. The concept was developed by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to their extinct relatives in his "Die Stammesgeschichte der Insekten", and the "crown" and "stem" group terminology was coined by R. P. S. Jefferies in 1979. Though formulated in the 1970s, the term was not commonly used until its reintroduction in 2000 by Graham Budd and Sören Jensen. Contents of the crown gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplocynodon
''Diplocynodon'' is an extinct genus of alligatoroid that lived during the Paleocene to Middle Miocene in Europe. It looked very similar to the modern caiman in that it was small and had bony armour scutes covering its neck, back, belly, and tail. The longest ''Diplocynodon'' recovered was 4 feet in length and probably fed on small fish, frogs, and took insects when young. In the nineteenth century, ''D. steineri'' was named from Styria, Austria and ''D. styriacus'' was named from Austria and France. A third Austrian species, ''Enneodon ungeri'', was placed in its own genus. The Austrian and French species of ''Diplocynodon'' were synonymized with ''E. ungeri'' in 2011, and because the name ''Diplocynodon'' has priority over ''Enneodon'', the species is now called ''D. ungeri''. Other genera have recently been found to be synonymous with ''Diplocynodon''. ''Hispanochampsa muelleri'' of Spain was determined to be synonymous with ''Diplocynodon'' in 2006, and ''Baryphracta deponaie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplocynodontinae
''Diplocynodon'' is an extinct genus of alligatoroid that lived during the Paleocene to Middle Miocene in Europe. It looked very similar to the modern caiman in that it was small and had bony armour scutes covering its neck, back, belly, and tail. The longest ''Diplocynodon'' recovered was 4 feet in length and probably fed on small fish, frogs, and took insects when young. In the nineteenth century, ''D. steineri'' was named from Styria, Austria and ''D. styriacus'' was named from Austria and France. A third Austrian species, ''Enneodon ungeri'', was placed in its own genus. The Austrian and French species of ''Diplocynodon'' were synonymized with ''E. ungeri'' in 2011, and because the name ''Diplocynodon'' has priority over ''Enneodon'', the species is now called ''D. ungeri''. Other genera have recently been found to be synonymous with ''Diplocynodon''. ''Hispanochampsa muelleri'' of Spain was determined to be synonymous with ''Diplocynodon'' in 2006, and ''Baryphracta deponaie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinosuchus
''Deinosuchus'' () is an extinct genus of alligatoroid crocodilian, related to modern alligators and caimans, that lived 82 to 73 million years ago (Ma), during the late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek ''deinos'' (δεινός), "terrible", and ''soukhos'' (σοῦχος), "crocodile". The first remains were discovered in North Carolina (United States) in the 1850s; the genus was named and described in 1909. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of ''Deinosuchus'' remains incomplete, but better cranial material found in recent years has expanded scientific understanding of this massive predator. Although ''Deinosuchus'' was far larger than any modern crocodile or alligator, with the largest adults measuring in total length, its overall appearance was fairly simi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 from the middle Campanian age Dinosaur Park Formation. It was a medium-sized alligatorid, with a maximum skull length greater than 40 centimeters (16 in). A number of species had been assigned to this genus over the years, including: ''L. acutidentatus'' ( Sternberg, 1932), from the Paleocene of Saskatchewan; ''L. formidabilis'' (Erickson, 1976), from the Paleocene of North Dakota and Wyoming; ''L. gilmorei'' (Mook, 1942), from the Campanian of Alberta; ''L. multidentatus'' (Mook, 1930); ''L. riggsi'' (Schmidt, 1938); ''L. sternbergii'' ( Gilmore, 1910), from the Maastrichtian (Late Cretaceous) of Colorado, Montana, North Dakota, South Dakota, and Wyoming; and ''L. wilsoni'' (Mook, 1959), from the Eocene of Wyoming. However, in 1997 ... [...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] |
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] |
Stem-based Taxon
Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a '' type'', which can be a specimen or a taxon of lower rank, and a description in words. Phylogenetic nomenclature is currently regulated by the '' International Code of Phylogenetic Nomenclature'' (''PhyloCode''). Definitions Phylogenetic nomenclature ties names to clades, groups consisting of an ancestor and all its descendants. These groups can equivalently be called monophyletic. There are slightly different ways of specifying the ancestor, which are discussed below. Once the ancestor is specified, the meaning of the name is fixed: the ancestor and all organisms which are its descendants are included in the named taxon. Listing all these organisms (i.e. providing a full circumscription) requires the full phylogenetic tree to be known. In practice, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligatoridae
The family Alligatoridae of crocodylians includes alligators, caimans and their extinct relatives. Phylogeny The superfamily Alligatoroidea includes all crocodilians (fossil and extant) that are more closely related to the American alligator than to either the Nile crocodile or the gharial. This is a stem-based definition for alligators, and is more inclusive than the crown group Alligatoridae. As a crown group, Alligatoridae only includes the last common ancestor of all extant (living) alligators, caimans, and their descendants (living or extinct), whereas Alligatoroidea, as a stem-based group, also includes more basal extinct alligator ancestors that are more closely related to living alligators than to crocodiles or gavialids. When considering only living taxa (neontology), this makes Alligatoroidea and Alligatoridae redundant. The simplified cladogram below shows Alligatoridae's relationships to other extant (living) crocodilians. The below detailed cladogram show ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
