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Lydekkerinidae
Lydekkerinidae is a family of stereospondyl temnospondyls that lived in the Early Triassic period. During this time period, lydekkerinids were widely distributed, with putative remains reported from Russia, Greenland, India, South Africa, Madagascar, Australia, and Antarctica. In contrast to most other stereospondyls, lydekkerinids were relatively small-bodied (most with skulls less than 10 cm in length). The type genus is ''Lydekkerina'', the namesake of the family and the best-known lydekkerinid. Description The identification of features shared among lydekkerinids (synapomorphies) necessarily varies depending on which taxa are considered to belong to this group (see further in next section). In the most expansive concept, the family includes the eponymous ''Lydekkerina'' (and junior synonyms like '''Broomulus''' and '''Limnoiketes'''), ''Eolydekkerina'' from South Africa, ''Deltacephalus'' from Madagascar, ''Luzocephalus'' from Russia and Greenland (which includes the '''Aqui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereospondyli
The Stereospondyli are a group of extinct temnospondyl amphibians that existed primarily during the Mesozoic period. They are known from all seven continents and were common components of many Triassic ecosystems, likely filling a similar ecological niche to modern crocodilians prior to the diversification of pseudosuchian archosaurs. Classification and anatomy The group was first defined by Zittel (1888) on the recognition of the distinctive vertebral anatomy of the best known stereospondyls of the time, such as ''Mastodonsaurus'' and '' Metoposaurus''. The term 'stereospondylous' as a descriptor of vertebral anatomy was coined the following year by Fraas, referring to a vertebral position consisting largely or entirely of the intercentrum in addition to the neural arch. While the name 'Stereospondyli' is derived from the stereospondylous vertebral condition, there is a diversity of vertebral morphologies among stereospondyls, including the diplospondylous (' tupilakosaurid') c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhytidostea
Rhytidostea is a clade of stereospondyl temnospondyls. It was erected in 2000 to include several temnospondyl groups distinct from the "higher" group of capitosaurs, including lydekkerinids, brachyopoids, and rhytidosteids. Rhytidosteans first appeared in the Permian period and underwent an evolutionary radiation during the Induan stage of the Early Triassic. Along with capitosaurs, rhytidosteans comprise much of the larger suborder Stereospondyli. Rhytidostea has often been considered the sister group of the clade Capitosauria, but has been placed in various other phylogenetic positions. In many studies, members of Rhytidostea are split, with lydekkerinids having a more basal position among stereospondyls while rhytidosteids and brachyopoids form a group placed among the more derived trematosaurian stereospondyls. Classification Schoch and Milner (2000) erected the clade Rhytidostea to include lydekkerinids, brachyopoids, and rhytidosteids. The clade was the sister taxon of C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereospondyl
The Stereospondyli are a group of extinct temnospondyl amphibians that existed primarily during the Mesozoic period. They are known from all seven continents and were common components of many Triassic ecosystems, likely filling a similar ecological niche to modern crocodilians prior to the diversification of pseudosuchian archosaurs. Classification and anatomy The group was first defined by Zittel (1888) on the recognition of the distinctive vertebral anatomy of the best known stereospondyls of the time, such as ''Mastodonsaurus'' and ''Metoposaurus''. The term 'stereospondylous' as a descriptor of vertebral anatomy was coined the following year by Fraas, referring to a vertebral position consisting largely or entirely of the intercentrum in addition to the neural arch. While the name 'Stereospondyli' is derived from the stereospondylous vertebral condition, there is a diversity of vertebral morphologies among stereospondyls, including the diplospondylous (' tupilakosaurid') co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temnospondyl
Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order (biology), order of small to giant tetrapods—often considered Labyrinthodontia, primitive amphibians—that flourished worldwide during the Carboniferous, Permian, and Triassic periods. A few species continued into the Jurassic and Cretaceous periods. Fossils have been found on every continent. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis, and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are considered amphibians, many had cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryobatrachus
''Cryobatrachus'' (from Greek, (krýos, "cold") and (batrakhos, "frog")) is an extinct genus of temnospondyl amphibian from the Early Triassic of Antarctica. The type species is ''Cryobatrachus kitchingi''. It is known from a partial skull and an imprint of the skull roof, both found in the Fremouw Formation of the Transantarctic Mountains at about 85° south latitude and described in 1974. Many small bone fragments have also been identified, although they cannot be attributed with certainty to ''C. kitchingi''. ''Cryobatrachus'' has been classified in the family Lydekkerinidae, as it is similar in appearance to the genus ''Lydekkerina'' from South Africa. Because only a small number of features distinguish it from other lydekkerinids, ''Cryobatrachus kitchingi'' has more recently been considered a ''nomen dubium'', meaning that its distinction from other better-known species may be unwarranted. Discovery and specimens Fossils of ''Cryobatrachus'' were first found by South Afr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lydekkerina
''Lydekkerina'' is an extinct genus of stereospondyl temnospondyl. It is the type genus of the family Lydekkerinidae. Fossils have been collected from Early Triassic deposits in South Africa and Australia. The type species is '' L. huxleyi'', first described in 1889. While most other stereospondyls were semiaquatic, ''Lydekkerina'' was exclusively terrestrial. Description ''Lydekkerina'' was a relatively small temnospondyl, growing up to around in length. Skulls range in length from in the smallest known individual to up to in larger individuals. The skull is wedge-shaped and has a parabolic outline with convex lateral margins. Shallow pits cover the surface of the skull. Teeth line the palate as well as the jaws, and some skulls even bear large ectopterygoid tusks on the underside of the skull. ''Lydekkerina'' can be distinguished from other lydekkerinids on the basis of several skull characteristics. One such feature is the presence of vomerine shagreen, tiny bumps cove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematosauridae
Trematosauridae are a family of large marine temnospondyl amphibians with many members. They first appeared during the Induan age of the Early Triassic, and existed until around the Carnian stage of the Late Triassic, although by then they were very rare. By the Middle Triassic they had become widespread throughout Laurasia and Gondwana with fossils being found in Europe, Asia, Madagascar, and Australia. They are one of the most derived families of the Trematosauroidea superfamily in that they are the only family that have fully marine lifestyles. Long, slender snouts that are characteristic of the trematosaurids, with some members having rostrums resembling those of modern-day gavials. Traditionally, two subfamilies within Trematosauridae can be identified, the relatively short-nosed Trematosaurinae and the long-nosed Lonchorhynchinae._A_third_subfamily,_Tertreminae.html" ;"title=".... A third subfamily, Tertreminae">.... A third subfamily, Tertreminae, was named in 2000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly .. ource for pronunciation./ref> It is contrasted with monophyly and paraphyly. For example, the biological characteristic of warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds; "warm-blooded animals" is therefore a polyphyletic grouping. Other examples of polyphyletic groups are algae, C4 photosynthetic plants, and edentates. Many taxonomists aim to avoid homoplasies in grouping taxa together, with a goal to identify and eliminate groups that are found to be polyphyletic. This is often the stimulus for major revisions of the classification schemes. Researchers concerned more with ecology than with systema ... [...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] |
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] |
Capitosauria
Capitosauria is an extinct group of large temnospondyl amphibians with simplified stereospondyl vertebrae. Mainly living as piscivores in lakes and rivers, the Capitosauria and its sister taxon Trematosauria were the only major labyrinthodonts that existed during the Mesozoic in ecological niches broadly similar to those of modern crocodiles, and some grew to very large sizes. At 6 meters in length, the Mid-Triassic '' Mastodonsaurus giganteus'' is not only thought to have been the largest capitosaur, but possibly also the largest amphibian to have lived. The latest known remains are from the Rhaetian of Germany and are referred to ''Cyclotosaurus''. Capitosauria was first named by Schoch and Milner (2000) and further described by Yates and Warren (2000), who assigned ''Lydekkerina'' and Mastodonsauroidea to it. It was described by Damiani (2001) under the name Mastodonsauroidea. In their phylogenetic analysis of temnospondyls, Ruta ''et al.'' (2007) placed ''Lydekkerina'' and it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capitosauroidea
The Mastodonsauroidea are an extinct superfamily of temnospondyl amphibians known from the Triassic. Fossils belonging to this superfamily have been found in North America, Greenland, Europe, Asia, and Australia. The genus ''Ferganobatrachus'' from the Jurassic of Asia was initially included in this superfamily but later reinterpreted as a brachyopid and given a new name Gobiops ''Gobiops'' is an extinct genus of temnospondyl from the Jurassic of Mongolia, China, and possibly Kyrgyzstan. The genus is represented by a single species, ''Gobiops desertus''. It was named in 1991 from the Late Jurassic Shar Teeg Beds of Mong .... ReferencesThe Paleobiology Database*& 2007 "Revision of the type material and nomenclature of ''Mastodonsaurus giganteus'' (Jaeger) (Temnospondyli) from the middle Triassic of Germany" ''Palaeontology'' 505:1245-1266 External links Vertebrate superfamilies Triassic temnospondyls Jurassic temnospondyls Early Triassic first appearances Middle J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
