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Procolophonomorph
Procolophonomorpha is an order or clade containing most parareptiles. Many papers have applied various definitions to the name, though most of these definitions have since been considered synonymous with modern parareptile clades such as Ankyramorpha and Procolophonia. The current definition of Procolophonomorpha, as defined by Modesto, Scott, & Reisz (2009), is that of as a stem-based group containing ''Procolophon'' and all taxa more closely related to it than to ''Milleretta''. It constitutes a diverse assemblage that includes a number of lizard-like forms, as well as more diverse types such as the pareiasaurs. Lee 1995, 1996, 1997 argues that turtles evolved from pareiasaurs, but this view is no longer considered likely. Rieppel and deBraga 1996 and deBraga and Rieppel, 1997 argue that turtles evolved from sauropterygians, and there is both molecular and fossil (''Pappochelys'') evidence for the origin of turtles among diapsid reptiles. Classification The following cladog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australothyris Smithi
''Australothyris'' is an extinct genus of basal procolophonomorph parareptile known from the Middle Permian (middle Capitanian stage) of ''Tapinocephalus'' Assemblage Zone, South Africa. The type and only known species is ''Australothyris smithi''. As the most basal member of Procolophonomorpha, ''Australothyris'' helped to contextualize the origin of this major parareptile subgroup. It has been used to support the hypotheses that procolophonomorphs originated in Gondwana and ancestrally possess temporal fenestrae, due to its large and fully enclosed temporal fenestra and South African heritage. It also possessed several unique features, including a high tooth number, long postfrontal, small interpterygoid vacuity, and a specialized interaction between the stapes and quadrate. Discovery Australothyris is known from a single specimen discovered at the Beukesplaas farm by Robert Smith in 1995. The fossil site at the Beukesplaas farm contains a diverse parareptile and synapsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australothyris
''Australothyris'' is an extinct genus of basal procolophonomorph parareptile known from the Middle Permian (middle Capitanian stage) of ''Tapinocephalus'' Assemblage Zone, South Africa. The type and only known species is ''Australothyris smithi''. As the most basal member of Procolophonomorpha, ''Australothyris'' helped to contextualize the origin of this major parareptile subgroup. It has been used to support the hypotheses that procolophonomorphs originated in Gondwana and ancestrally possess temporal fenestrae, due to its large and fully enclosed temporal fenestra and South African heritage. It also possessed several unique features, including a high tooth number, long postfrontal, small interpterygoid vacuity, and a specialized interaction between the stapes and quadrate. Discovery Australothyris is known from a single specimen discovered at the Beukesplaas farm by Robert Smith in 1995. The fossil site at the Beukesplaas farm contains a diverse parareptile and synapsid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microleter
''Microleter'' is an extinct genus of basal procolophonomorph parareptiles which lived in Oklahoma during the Early Permian period. The type and only known species is ''Microleter mckinzieorum''. ''Microleter'' is one of several parareptile taxa described from the Richards Spur fissure fills, and can be characterized from its high tooth count, lacrimal/ narial contact, short postfrontal, and slit-like temporal emargination edged by the postorbital, jugal, squamosal, and quadratojugal. Contrary to '' Australothyris'', which had a similar phylogenetic position as a basal procolophonomorph, ''Microleter'' suggests that early parareptile evolution occurred in Laurasia and that multiple lineages developed openings or emarginations in the temporal region. Discovery The only known specimen of ''Microleter'' is a well-preserved skull and lower jaw designated as OMNH 71306, the holotype specimen. It was found at the Dolese Brothers limestone quarry near Richards Spur in Comanch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ankyramorpha
Ankyramorpha ("anchor forms") is an extinct clade of procolophonomorph parareptiles which lived between the early Cisuralian epoch (middle Sakmarian stage) to the latest Triassic period (latest Rhaetian stage) of Africa, Antarctica, Asia, Australia, Europe, North America and South America.Jalil, N. E., & Janvier, P. (2005). Les pareiasaures (Amniota, Parareptilia) du Permien supérieur du Bassin d’Argana, Maroc. Geodiversitas, 27(1), 35-132. This clade was named in a 1996 parareptile study by Michael deBraga and Robert R. Reisz. They provided the name Ankyramorpha for a newly recognized clade encompassing "the most recent common ancestor of Procolophonia and Lanthanosuchoidea and all its descendants", and this clade name sees continued use among modern parareptile studies. A similar name, Hallucicrania, was provided in an earlier 1995 study by Michael S. Y. Lee, who defined it as the node-based taxon formed by the most recent common ancestor of lanthanosuchids and " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gzhelian
The Gzhelian ( ) is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the youngest stage of the Pennsylvanian, the youngest subsystem of the Carboniferous. The Gzhelian lasted from to Ma. It follows the Kasimovian age/stage and is followed by the Asselian age/stage, the oldest subdivision of the Permian system. The Gzhelian is more or less coeval with the Stephanian Stage of the regional stratigraphy of Europe. Name and definition The Gzhelian is named after the Russian village of Gzhel (russian: Гжель), nearby Ramenskoye, not far from Moscow. The name and type locality were defined by Sergei Nikitin (1850–1909) in 1890. The base of the Gzhelian is at the first appearance of the Fusulinida genera '' Daixina'', '' Jigulites'' and '' Rugosofusulina'', or at the first appearance of the conodont ''Streptognathodus zethus''. The top of the stage (the base of the Permian system) is at the first appearance of the conodont ''Strepto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diapsid
Diapsids ("two arches") are a clade of sauropsids, distinguished from more primitive eureptiles by the presence of two holes, known as temporal fenestrae, in each side of their skulls. The group first appeared about three hundred million years ago during the late Carboniferous period. All diapsids other than the most primitive ones in the clade Araeoscelidia are sometimes placed into the clade Neodiapsida. The diapsids are extremely diverse, and include birds and all modern reptile groups, including turtles, which were historically thought to lie outside the group. Although some diapsids have lost either one hole (lizards), or both holes (snakes and turtles), or have a heavily restructured skull (modern birds), they are still classified as diapsids based on their ancestry. At least 17,084 species of diapsid animals are extant: 9,159 birds, and 7,925 snakes, lizards, tuatara, turtles, and crocodiles. Characteristics The name Diapsida means "two arches", and diapsids are tradit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pareiasaurs
Pareiasaurs (meaning "cheek lizards") are an extinct clade of large, herbivorous parareptiles. Members of the group were armoured with scutes which covered large areas of the body. They first appeared in southern Pangea during the Middle Permian, before becoming globally distributed during the Late Permian. Pareiasaurs were the largest reptiles of the Permian, reaching sizes equivalent to those of contemporary therapsids. Pareiasaurs became extinct at the end of the Permian during the Permian-Triassic extinction event. Description Pareiasaurs ranged in size from long, and may have weighed up to . They were stocky, with short tails, small heads, robust limbs, and broad feet. The cow-sized species ''Bunostegos'', which lived 260 million years ago, is the earliest known example of a tetrapod with a fully erect posture as its legs were positioned directly under its body. Pareiasaurs were protected by bony scutes called osteoderms that were set into the skin. Their heavy skulls wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropterygia
Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became extinct at the end of that period. The plesiosaurs would continue to diversify until the end of the Mesozoic. Sauropterygians are united by a radical adaptation of their pectoral girdle, adapted to support powerful flipper strokes. Some later sauropterygians, such as the pliosaurs, developed a similar mechanism in their pelvis. Uniquely among reptiles, sauropterygians moved their tail vertically like modern cetaceans and sirenians. Origins and evolution The earliest sauropterygians appeared about 247 million years ago (Ma), at the start of the Middle Triassic: the first definite sauropterygian with exact stratigraphic datum lies within the Spathian division of the Olenekian era in South China. Early examples were small (around 60 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pappochelys
''Pappochelys'' ( meaning "grandfather turtle" in Greek) is an extinct genus of diapsid reptile possibly related to turtles. The genus contains only one species, ''Pappochelys rosinae'', from the Middle Triassic of Germany, which was named by paleontologists and Hans-Dieter Sues in 2015. The discovery of ''Pappochelys'' provides strong support for the placement of turtles within Diapsida, a hypothesis that has long been suggested by molecular data, but never previously by the fossil record. It is morphologically intermediate between the definite stem-turtle ''Odontochelys'' from the Late Triassic of China and '' Eunotosaurus'', a reptile from the Middle Permian of South Africa. Description ''Pappochelys'' had a wide body, small skull, and a long tail that makes up about half of the total body length, which is up to . The skull is pointed with large eye sockets. Several turtle-like features are present, including expanded ribs and gastralia that seem to be precursors of a shel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parareptilia
Parareptilia ("at the side of reptiles") is a subclass or clade of basal sauropsids (reptiles), typically considered the sister taxon to Eureptilia (the group that likely contains all living reptiles and birds). Parareptiles first arose near the end of the Carboniferous period and achieved their highest diversity during the Permian period. Several ecological innovations were first accomplished by parareptiles among reptiles. These include the first reptiles to return to marine ecosystems (mesosaurs), the first bipedal reptiles (bolosaurids such as '' Eudibamus''), the first reptiles with advanced hearing systems ( nycteroleterids and others), and the first large herbivorous reptiles (the pareiasaurs). The only parareptiles to survive into the Triassic period were the procolophonoids, a group of small generalists, omnivores, and herbivores. The largest family of procolophonoids, the procolophonids, rediversified in the Triassic, but subsequently declined and became extinct by t ... [...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] |
Procolophon
''Procolophon'' is a genus of lizard-like procolophonid parareptiles that first appeared in the Early Triassic (Induan) of South Africa, Brazil, and Antarctica. It persisted through the Permian–Triassic extinction event, but went extinct in the beginning of the Early Middle Triassic. The type species is ''P. trigoniceps''. History of discovery The first ''Procolophon'' fossil was discovered in the 1870s in Donnybrook, an area southwest of Pietermaritzburg in present-day Kwa-Zulu Natal of South Africa. The fossil was accessioned to Harry Seeley, who described the fossil in 1878. Numerous other fossils have been recovered since from localities across the Eastern Cape and Free State provinces of South Africa. Description ''Procolophon'' reached a length up to , and is considered to have been a small herbivore or insectivore. The skull of ''Procolophon'' is distinct because of its latero-posteriorly facing paired cheek spikes, along with spiked dermal ossicles. Paleonto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
