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Reptiliomorph
Reptiliomorpha (meaning reptile-shaped; in PhyloCode known as ''Pan-Amniota'') is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians). It was defined by Michel Laurin (2001) and Vallin and Laurin (2004) as the largest clade that includes ''Homo sapiens'', but not '' Ascaphus truei'' (tailed frog). Laurin and Reisz (2020) defined Pan-Amniota as the largest total clade containing ''Homo sapiens'', but not '' Pipa pipa'', '' Caecilia tentaculata'', and '' Siren lacertina''. The informal variant of the name, "reptiliomorphs", is also occasionally used to refer to stem-amniotes, i.e. a grade of reptile-like tetrapods that are more closely related to amniotes than they are to lissamphibians, but are not amniotes themselves; the name is used in this meaning e.g. by Ruta, Coates and Quicke (2003). An alternative name, " Anthracosauria", is also commonly used for the group, but is confusin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eldeceeon
''Eldeceeon'' is an extinct genus of reptiliomorph from the Mississippian (early Carboniferous) of Scotland. It is known from two fossil specimens found within the Viséan-age East Kirkton Quarry in West Lothian. The type and only species, ''E. rolfei'', was named in 1994. ''Eldeceeon'' is thought to be closely related to embolomeres, but it has several distinguishing features including long limbs and a short trunk. Initially known from two crushed partial skeletons, additional specimens have been reported by Ruta & Clack (2006). ''Eldeceeon'' was redescribed by Ruta, Clack, & Smithson (2020). The redescription supported affinities with ''Silvanerpeton'', reconstructed a skull with larger eyes and a shorter snout, and emphasized potential correlations for an enlarge '' puboischiofemoralis internus'' 2 muscle. Description In the East Kirkton Quarry, fossils of ''Eldeceeon'' were found alongside another reptiliomorph called ''Silvanerpeton''. These genera are closely related to ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amniotes
Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the Carboniferous period. Amniota is defined as the smallest crown clade containing humans, the Greek tortoise, and the Nile crocodile. Amniotes are distinguished from the other living tetrapod clade — the non-amniote lissamphibians (frogs/ toads, salamanders/ newts and caecilians) — by: the development of three extraembryonic membranes ( amnion for embryonic protection, chorion for gas exchange, and allantois for metabolic waste disposal or storage); thicker and keratinized skin; costal respiration (breathing by expanding/constricting the rib cage); the presence of adrenocortical and chromaffin tissues as a discrete pair of glands near their kidneys; more complex kidneys; the presence of an astragalus for better ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amniota
Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the Carboniferous period. Amniota is defined as the smallest crown clade containing humans, the Greek tortoise, and the Nile crocodile. Amniotes are distinguished from the other living tetrapod clade — the non-amniote lissamphibians (frogs/ toads, salamanders/newts and caecilians) — by: the development of three extraembryonic membranes ( amnion for embryonic protection, chorion for gas exchange, and allantois for metabolic waste disposal or storage); thicker and keratinized skin; costal respiration (breathing by expanding/constricting the rib cage); the presence of adrenocortical and chromaffin tissues as a discrete pair of glands near their kidneys; more complex kidneys; the presence of an astragalus for better extremity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptilia
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and amniotic development. Living traditional reptiles comprise four orders: Testudines, Crocodilia, Squamata, and Rhynchocephalia. About 12,000 living species of reptiles are listed in the Reptile Database. The study of the traditional reptile orders, customarily in combination with the study of modern amphibians, is called herpetology. Reptiles have been subject to several conflicting taxonomic definitions. In Linnaean taxonomy, reptiles are gathered together under the class Reptilia ( ), which corresponds to common usage. Modern cladistic taxonomy regards that group as paraphyletic, since genetic and paleontological evidence has determined that birds (class Aves), as members of Dinosauria, are more closely related to living crocodilians than to other reptiles, and are thus nested among reptiles from an evolutionary perspective. Many cladistic systems therefore redefine Reptilia as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapod
A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetrapoda (). Tetrapods include all Neontology#Extant taxa versus extinct taxa, extant and Extinction, extinct amphibians and amniotes, with the latter in turn Evolution, evolving into two major clades, the Sauropsida, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (extinct pelycosaur, "pelycosaurs", therapsids and all extant mammals, including Homo sapiens, humans). Hox gene mutations have resulted in some tetrapods becoming Limbless vertebrate, limbless (snakes, legless lizards, and caecilians) or two-limbed (cetaceans, sirenians, Bipedidae, some lizards, kiwi (bird), kiwis, and the extinct moa and elephant birds). Nevertheless, they still qualify as tetrapods through their ancestry, and some retain a pair of ves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diadectomorpha
Diadectomorpha is a clade of large tetrapods that lived in Euramerica during the Carboniferous and Early Permian periods and in Asia during Late Permian (Wuchiapingian), They have typically been classified as advanced reptiliomorphs (transitional between "amphibians" ''sensu lato'' and amniotes) positioned close to, but outside of the clade Amniota, though some recent research has recovered them as the sister group to the traditional Synapsida within Amniota, based on inner ear anatomy and cladistic analyses. They include both large (up to 2 meters long) carnivorous and even larger (to 3 meters) herbivorous forms, some semi-aquatic and others fully terrestrial. The diadectomorphs seem to have originated during late Mississippian times, although they only became common after the Carboniferous rainforest collapse and flourished during the Late Pennsylvanian and Early Permian periods. Anatomy Diadectomorphs possessed both amphibian-like and amniote-like characteristics. Origin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solenodonsaurus
''Solenodonsaurus'' ("single-tooth lizard") is an extinct genus of reptiliomorphs that lived in what is now Czech Republic, during the Westphalian stage. Description ''Solenondosaurus'' had snout-vent length with a skull length . ''Solenodonsaurus'' shows a curious mix of characters making it difficult to place phylogenetically. The teeth lack labyrinthodont folding of the enamel, and it skull has a much smaller otic notch than seen in other reptiliomorph amphibians. Yet general build ties it in with the Diadectomorpha. Laurin, M. and Rize R.R. (1999): A new study of ''Solenodonsaurus janenschi'', and a reconsideration of amniote origins and stegocephalian evolution. ''Canadian Journal of Earth Science'', no 36 (8): pp 1239–1255 (1999)/ref> Paleobiology ''Solenodonsaurus'' was likely best adapted to life on land, as opposed to living in an aquatic environment like many other early tetrapods. The limbs and pelvis are incomplete in all known specimens of ''Solenodonsaurus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embolomeri
Embolomeri is an Order (biology), order of Tetrapod, tetrapods or Stem-group, stem-tetrapods, possibly members of Reptiliomorpha. Embolomeres first evolution, evolved in the Early Carboniferous (Mississippian age, Mississippian) Period and were the largest and most successful predatory tetrapods of the Late Carboniferous (Pennsylvanian (geology), Pennsylvanian) Period. They were specialized semiaquatic predators with long bodies for eel-like undulatory swimming. Embolomeres are characterized by their Vertebra, vertebral centra, which are formed by two cylindrical segments, the pleurocentrum at the rear and intercentrum at the front. These segments are equal in size. Most other tetrapods have pleurocentra and intercentra which are drastically different in size and shape. Embolomeres were among the earliest large carnivorous tetrapods, with members such as the crocodilian-like ''Proterogyrinus'' appearing in the Viséan, Visean stage of the Carboniferous. They declined in diversity d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silvanerpeton
''Silvanerpeton'' is an extinct genus of early reptiliomorph found by Stan Wood in the East Kirkton Quarry of West Lothian, Scotland, in a sequence from the Brigantian substage of the Viséan ( Lower Carboniferous). The find is important, as the quarry represents terrestrial deposits from Romer's gap, a period poor in fossils where the higher groups "labyrinthodonts" evolved. The type species ''Silvanerpeton miripedes'' was named by Jennifer A. Clack in 1993/1994. The generic name is derived from Silvanus, the Roman god of woods. The specific name means "wondrous feet" in Latin. The holotype is specimen UMZC T1317, a skeleton with skull and skin impressions. Description In life ''Silvanerpeton'' was about 40 cm (1 ft) long. Some paleontologists think it was semi-aquatic as an adult, others believe only young individuals of ''Silvanerpeton'' were aquatic and the adults were fully terrestrial. Classification Based on a remarkably well preserved humerus and other tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seymouriamorpha
Seymouriamorpha were a small but widespread group of limbed vertebrates (tetrapods). They have long been considered stem group, stem-amniotes (reptiliomorphs), and most paleontologists still accept this point of view, but some analyses suggest that seymouriamorphs are stem-tetrapods (not more closely related to Amniota than to Lissamphibia). Many seymouriamorphs were terrestrial or semi-aquatic. However, aquatic larvae bearing external gills and grooves from the lateral line system have been found, making them unquestionably non-amniotes. As they matured, they became more terrestrial and reptile-like. They ranged from 30 cm (1 ft) long lizard-sized creatures to the 1.5 m (5 ft) long ''Enosuchus''. If seymouriamorphs are reptiliomorphs, they were the distant relatives of amniotes. Seymouriamorphs are divided into three main groups: Kotlassiidae, Discosauriscidae, and Seymouriidae, which includes the best-known genus, ''Seymouria''. The last seymouriamorphs became Permian-Triassic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casineria
''Casineria'' is an extinct genus of tetrapodomorph which lived about 340–334 million years ago in the Mississippian (geologic period), Mississippian epoch of the Carboniferous period. Its Generic name (biology), generic name, ''Casineria'', is a latinization of Cheese Bay, the site near Edinburgh, Scotland, where the holotype fossil was found. When originally described in 1999, it was identified as a transitional fossil noted for its mix of basal (amphibian-like) and advanced (reptile-like) characteristics, putting it at or very near the origin of the amniotes, the group containing all Mammal, mammals, Bird, birds, modern reptiles, and other descendants of their reptile-like Most recent common ancestor, common ancestor. However, the sole known fossil is lacking key elements such as a skull, making exact analysis difficult. As a result, the classification of ''Casineria'' has been more controversial in analyses conducted since 1999. Other proposed affinities include a placement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chroniosuchia
Chroniosuchia is a group of tetrapods that lived from the Middle Permian to Late Triassic in what is now Kyrgyzstan, China and Germany, Eastern Europe. Chroniosuchians are often thought to be reptiliomorphs, but some recent phylogenetic analyses suggest instead that they are stem-tetrapods. They were all rather short limbed with a strong tail and elongated snout, somewhat resembling modern crocodiles. The group is traditionally considered to be a suborder or order of labyrinthodonts. Chroniosuchians likely had ecological niches as riverside predators, and may have been outcompeted by semiaquatic true reptiles such as phytosaurs in the late Triassic. Most forms bore a heavy armour of scutes along the back, possibly for protection against land born predators like therapsids, or to strengthen the axial skeleton for terrestrial locomotion. Indeed, femoral microanatomy of '' Chroniosaurus'' suggests that it was amphibious to terrestrial. Description The most distinguishing features ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
