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Planocrania
''Planocrania'' is an extinct genus of eusuchian crocodyliforms from what is now China. Two species are currently known to belong to the genus. History The type species, ''Planocrania datangensis'', was named in 1976 from material found from Nanxiong in Guangdong Province, China, and the new genus ''Planocrania'' was placed in a newly erected family Planocraniidae. A second species, ''Planocrania hengdongensis'', is known from Hengdong County in Hunan Province and was described in 1984. ''Planocrania'' was subsequently included in the family Pristichampsidae along with the genus ''Pristichampsus''. Both genera were previously assigned to the subfamily Pristichampsinae within the family Crocodylidae before they were placed in their own family, the Pristichampsidae. However, in a 2013 phylogenetic analysis, the two Asian species of ''Planocrania'' were found to be most closely related to the North American and European ''Boverisuchus'', and the family Planocraniidae was reinstat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planocraniidae
Planocraniidae is an extinct family (biology), family of eusuchian crocodyliforms known from the Paleogene of Asia, Europe and North America. The family was coined by Li in 1976, and contains three genera, ''Boverisuchus'', ''Duerosuchus'' and ''Planocrania''. Planocraniids were highly specialized crocodyliforms that were adapted to living on land. They had extensive body armor, long legs, and blunt claws resembling hooves, and are sometimes informally called "hoofed crocodiles". Classification Prior to 2013, the term Pristichampsidae/Pristichampsinae was used for this group. However, the type specimen of ''Pristichampsus'' was found to be undiagnostic, and considered to be a ''nomen dubium''. As such, Brochu (2013) transferred the other species placed in ''Pristichampsus'' to ''Boverisuchus'', and resurrected Planocraniidae to replace Pristichampsidae/Pristichampsinae as the name for the clade. Brochu cladistically defined Planocraniidae as ''Planocrania hengdongensis'' and croco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boverisuchus
''Boverisuchus'' is an extinct genus of planocraniid crocodyliforms known from the middle Eocene (Lutetian stage) of Germany and western North America. It grew to approximately in length. History The type species ''Boverisuchus magnifrons'' was first named by paleontologist Oskar Kuhn in 1938, from the Lutetian of Germany alongside ''Weigeltisuchus geiseltalensis''. Most paleontologists have considered both species to represent junior synonyms of the type species of ''Pristichampsus'', ''P. rollinatii''. Following a revision of the genus ''Pristichampsus'' by Brochu (2013), ''P. rollinati'' was found to be based on insufficiently diagnostic material and therefore is a ''nomen dubium'' while ''Boverisuchus'' was reinstated as a valid genus. Brochu (2013) also assigned ''Crocodylus vorax'', which has been referred to as ''Pristichampsus vorax'' since Langston (1975), as the second species of ''Boverisuchus''. According to Brochu (2013), material from the middle Eocene of Italy and ... [...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] |
Scientifically Described
A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have been described previously or are related. In order for species to be validly described, they need to follow guidelines established over time. Zoological naming requires adherence to the ICZN code, plants, the ICN, viruses ICTV, and so on. The species description often contains photographs or other illustrations of type material along with a note on where they are deposited. The publication in which the species is described gives the new species a formal scientific name. Some 1.9 million species have been identified and described, out of some 8.7 million that may actually exist. Millions more have become extinct throughout the existence of life on Earth. Naming process A name of a new species becomes valid (available in zool ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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] |
Brevirostres
Brevirostres is a paraphyletic group of crocodilians that included alligatoroids and crocodyloids. Brevirostres are crocodilians with small snouts, and are distinguished from the long-snouted gharials. It is defined phylogenetically as the last common ancestor of ''Alligator mississippiensis'' (the American alligator) and ''Crocodylus niloticus'' (the Nile crocodile) and all of its descendants. This classification was based on morphological studies primarily focused on analyzing skeletal traits of living and extinct fossil species, and placed the gharials outside the group due to their unique skull structure, and can be shown in the simplified cladogram below: However, recent molecular studies using DNA sequencing have rejected Brevirostres upon finding the crocodiles and gavialids to be more closely related than the alligators. The new clade Longirostres was named by Harshman ''et al.'' in 2003, and can be shown in the cladogram below: History Brevirostres was first named by ... [...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] |
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] |
Basal (phylogenetics)
In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, 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, Phylogenetic diversity, 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 cladogenesis, diversification. However, such a correlation does not make a given ca ... [...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] |
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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