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Krabisuchus
''Krabisuchus'' is an extinct genus of alligatoroid crocodylian that existed in what is now Thailand during the Eocene. It was first named by paleontologists Jeremy A. Martin and Komsorn Lauprasert in 2010, and the type species is ''K. siamogallicus''. Fossils have been found from the Krabi Basin of southern Thailand and include mostly cranial and mandibular elements as well as some postcranial remains. ''Krabisuchus'' is currently the most well known primitive alligatoroid from Asia; previously, these animals were only represented in Asia by a few fragmentary remains from China. The fossil record of alligatoroids is much more extensive in Europe and North America, where most taxa have been described. Description Growing to approximately in length, ''Krabisuchus'' was a small alligatoroid that was much smaller than the living alligator. Like the alligator, it had a blunt snout. ''Krabisuchus'' also had a raised skull similar to the extinct alligatorine ''Arambourgia'' and li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orientalosuchina
Orientalosuchina is an extinct clade of alligatoroid crocodylians from South and East Asia that lived during the Paleocene and Eocene. The clade was named as the result of a 2019 study by Massonne ''et al.'' that included several extinct alligatoroid taxa from Asia and found that they were all closely related and together formed a monophyletic clade as basal members of Alligatoroidea, as shown in the cladogram below: Some studies have disputed this placement of ''Jiangxisuchus'' within Orientalosuchina as an alligatoroid, instead recovering ''Jiangxisuchus'' as a basal member of Crocodyloidea Crocodyloidea is one of three superfamilies of crocodilians, the other two being Alligatoroidea and Gavialoidea, and it includes the crocodiles. Crocodyloidea may also include the extinct Mekosuchinae, native to Australasia from the Eocene to th .... References Crocodilians Paleocene reptiles of Asia Paleocene crocodylomorphs {{paleo-archosaur-stub ... [...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] |
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 mississippi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligatorine
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 mississippiensis'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodile
Crocodiles (family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans (family Alligatoridae), the gharial and false gharial (family Gavialidae) among other extinct taxa. Although they appear similar, crocodiles, alligators and the gharial belong to separate biological families. The gharial, with its narrow snout, is easier to distinguish, while morphological differences are more difficult to spot in crocodiles and alligators. The most obvious external differences are visible in the head, with crocodiles having narrower and longer heads, with a more V-shaped than a U-shaped snout compared to alligators and caimans. Another obvious trait is that the upper and lower jaws of the crocodiles are the same width, and the teeth in the lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cartography Of Europe
The earliest cartographic depictions of Europe are found in early world maps. In classical antiquity, ''Europe'' was assumed to cover the quarter of the globe north of the Mediterranean, an arrangement that was adhered to in medieval T and O maps. Ptolemy's world map of the 2nd century already had a reasonably precise description of southern and western Europe, but was unaware of particulars of northern and eastern Europe. Medieval maps such as the Hereford Mappa Mundi still assumed that Scandinavia was an island. Progress was made in the 16th century, and Gerard Mercator gave an accurate representation of all of Europe, including Scandinavia shown as a peninsula. See also *History of Cartography *Geography of Europe *Cartography of Asia * Cartography of Africa *Boundaries between continents Determining the boundaries between the continents of Earth is generally a matter of geographical convention. Several slightly different conventions are in use. The number of continen ... [...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] |
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 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligatoroidea
Alligatoroidea is one of three superfamilies of crocodylians, the other two being Crocodyloidea and Gavialoidea. Alligatoroidea evolved in the Late Cretaceous period, and consists of the alligators and caimans, as well as extinct members more closely related to the alligators than the two other groups. Evolution The superfamily Alligatoroidea is thought to have split from the crocodile-gharial lineage in the late Cretaceous, about 80 million years ago, but possibly as early as 100 million years ago based on molecular phylogenetics. '' Leidyosuchus'' of Alberta is the earliest known genus. Fossil alligatoroids have been found throughout Eurasia as land bridges across both the North Atlantic and the Bering Strait have connected North America to Eurasia during the Cretaceous, Paleogene, and Neogene periods. Alligators and caimans split in North America during the early Tertiary or late Cretaceous (about 53 million to about 65 million years ago) and the latter reached South A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (phylogeny)
In phylogenetics, basal is the direction of the ''base'' (or root) of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a ' key innovation' implies some degree of correlation between evolutionary innovation and diversification. However, such a correlation does not make a given case predicable, so ancestral characters should not be imputed to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
