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Diapsids
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 earliest traditionally identified diapsids, the araeoscelidians, 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 often 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. All modern reptiles and birds are placed within the neodiapsid subclade Sauria. 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 sn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drepanosauromorpha
Drepanosaurs (members of the clade Drepanosauromorpha) are a group of extinct reptiles that lived between the Carnian and Rhaetian stages of the late Triassic Period, approximately between 230 and 210 million years ago. The various species of drepanosaurs were characterized by a bird-like skull, a barrell shaped body, and a horizontally narrow tail. A number of drepanosaurs had specialized grasping limbs and often prehensile tails similar to those of chameleons. Drepanosaurs are generally thought to have been arboreal (tree-dwelling), and probably insectivores. Some studies have alternately suggested fossorial (digging) and aquatic lifestyles for some members. Fossils of drepanosaurs have been found in North America (Arizona, New Mexico, New Jersey, Utah) and Europe (England and northern Italy). The name is taken from the family's namesake genus '' Drepanosaurus'', which means "sickle lizard," a reference to their strongly curved claws. Some studies have included Drepanosaurs with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avicephala
Avicephala ("bird heads") is a potentially polyphyletic grouping of extinct diapsid reptiles that lived during the Late Permian and Triassic periods characterised by superficially bird-like skulls and arboreal lifestyles. As a clade, Avicephala is defined as including the gliding weigeltisaurids and the arboreal drepanosaurs to the exclusion of other major diapsid groups. This relationship is not recovered in the majority of phylogenetic analyses of early diapsids and so Avicephala is typically regarded as an artificial or unnatural grouping. However, the clade was recovered again in 2021 following a redescription of '' Weigeltisaurus'', raising the possibility that the clade may be valid after all, although subsequent analyses have not supported this result. Description Avicephalans were named in reference to their pointed, lightly constructed, superficially bird-like skulls. The resemblance is especially striking in some drepanosaurs such as '' Megalancosaurus'' which possess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parareptilia
Parareptilia ("near-reptiles") is an extinct group of basal sauropsids (" reptiles"), traditionally 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] |
Weigeltisauridae
Weigeltisauridae is a family of gliding neodiapsid reptiles that lived during the Late Permian, between 259.51 and 251.9 million years ago. Fossils of weigeltisaurids have been found in Madagascar, Germany, Great Britain, and Russia. They are characterized by long, hollow rod-shaped bones extending from the torso that probably supported wing-like membranes. Similar membranes are also found in several other extinct reptiles such as kuehneosaurids and '' Mecistotrachelos'', as well as living gliding lizards, although each group evolved these structures independently. Skeleton The skulls and jaws of weigeltisaurids are ornamented with horns and tubercles, including chameleon-like frills. The torso and limbs are slender. The skeletons of weigeltisaurds are lightened by large air spaces (skeletal pneumaticity) within the bones. The phalanges of the hands and feet are elongate contrasting strongly with those of most other primitive diapsids, but are similar to those of modern arbor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claudiosaurus
''Claudiosaurus'' (''claudus'' is Latin for 'lameness' and ''saurus'' means 'lizard') is an extinct genus of diapsid reptiles from the Late Permian Sakamena Formation of the Morondava Basin, Madagascar. It has been suggested to be semi-aquatic. History and discovery ''Claudiosaurus'' is known from the Sakamena Formation of Madagascar. ''Claudiosaurus'' is found from the Late Permian. Although a paper mentions that they have been also found in Early Triassic deposits of Madagascar, citation does not mention that ''Claudiosaurus'' is from Triassic. Description Individuals of ''Claudiosaurus'' reached a body length of approximately . The body form of ''Claudiosaurus'' is generally similar to those of other basal diapsids, although the neck of ''Claudiosaurus'' is somewhat elongated, with 8 cervical vertebrae, and had a proportionally small head. The body has 16 trunk vertebrae with gastralia present on the underside, and the tail has at least 45 caudal vertebrae. The jaws ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tangasauridae
Tangasauridae is an extinct family of diapsids known from fossil specimens from Madagascar, Kenya and Tanzania that are Late Permian to Early Triassic in age. Fossils have been found of numerous specimens of common members of this family such as '' Hovasaurus'' in different stages of ontogenic development. Recent material from the Middle Sakamena Formation of the Morondava Basin of Madagascar that dates back to the early Triassic period suggests that the Tangasauridae were relatively unaffected by the Permian-Triassic extinction event. Description and phylogeny Tangasaurids are known to have been a highly derived group of diapsids. One subfamily, Kenyasaurinae, is composed of taxa that were fully terrestrial. They had long toes and highly developed sternums that made them well suited to life on land. On the other hand, the other subfamily, Tangasaurinae, is composed of taxa that were adapted to an aquatic life. They had webbed feet and a laterally compressed tails that al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Youngina
''Youngina'' (named after John Young (1823–1900)) is an extinct genus of diapsid reptile from the Late Permian Beaufort Group ('' Tropidostoma''-'' Dicynodon'' zones) of the Karoo Red Beds of South Africa. This, and a few related forms, make up the family Younginidae, within the order Eosuchia (proposed by Broom in 1914). Eosuchia, having become a wastebasket taxon for many probably distantly-related primitive diapsid reptiles ranging from the Late Carboniferous to the Eocene, Romer proposed that it be replaced by Younginiformes (that included Younginidae and the Tangasauridae, ranging from the Permian to the Triassic). Taxonomy ''Youngina'' is known from several specimens. Many of these were attributed to as separate genera and species (such as ''Youngoides'' and ''Youngopsis''), but it was later realized that they were not distinct from ''Y. capensis''. The holotype specimen of ''Youngina'', discovered by Broom himself, was described briefly in 1914. The "''Youngoide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Younginidae
Younginidae is an extinct family of diapsid reptiles from the Late Permian. In a phylogenetic context, younginids are near the base of the clade Neodiapsida. The only species definitively a member of the Younginidae is '' Youngina capensis'' from the Late Permian of South Africa. Several genera have historically been assigned to this family, though more recent phylogenetic analyses have supported relationships with other clades. '' Heleosuchus griesbachi'' from the Late Permian of South Africa may also be a member of the family. Younginidae was traditionally assigned to Eosuchia, an order containing an assemblage of basal diapsids now thought to represent an evolutionary grade rather than a true clade. In 1945 paleontologist Alfred Romer reclassified Younginidae within a new group, Younginiformes, grouping it with the families Tangasauridae and Prolacertidae. Romer considered Younginidae to include many genera that are no longer classified as younginids: '' Paliguana'', '' P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choristodera
Choristodera (from the Greek χωριστός ''chōristos'' + δέρη ''dérē'', 'separated neck') is an extinct order of semiaquatic diapsid reptiles that ranged from the Middle Jurassic, or possibly Triassic, to the Miocene (168 to 20 or possibly 11.6 million years ago). Choristoderes are morphologically diverse, with the best known members being the crocodile-like neochoristoderes such as '' Champsosaurus''. Other choristoderans had lizard-like or long necked morphologies. Choristoderes appear to have been confined to the Northern Hemisphere, having been found in North America, Asia, and Europe, and possibly also North Africa. Choristoderes are generally thought to be derived neodiapsids that are close relatives or members of Sauria. History of discovery Choristodera was erected in 1876, originally as a suborder of Rhynchocephalia by Edward Drinker Cope to contain '' Champsosaurus,'' which was described from Late Cretaceous strata of Montana by Cope in the same paper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acallosuchus
''Acallosuchus'' (meaning "ugly crocodile" in Greek) is an extinct genus of reptile from the Triassic Chinle Formation of the southwestern United States. Although it was discovered in 1923, ''Acallosuchus'' was not described until 1995, when the type species ''A. rectori'' was named. The taxonomy classification of ''Acallosuchus'' is uncertain. Although it is known to be a neodiapsid reptile, it has not been assigned with confidence to any particular group of neodiapsids. History In 1923, paleontologist Charles Lewis Camp discovered a bone in the Chinle Formation in what is now Petrified Forest National Park. It was found on top of a ''Placerias'' jaw in an area called Crocodile Hill, part of the late Carnian-age Blue Mesa Member of the formation. The bone included the skull and lower jaws of a reptile, but when Camp removed it from the surrounding rock, then it broke apart. Camp described the skull as being long, with a broken rostrum, and thought it belonged to a pterosaur or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araeoscelidia
Araeoscelidia or Araeoscelida is a clade of extinct tetrapods (traditionally classified as diapsid reptiles) superficially resembling lizards, extending from the Late Carboniferous to the Early Permian. The group contains the genera '' Araeoscelis'', ''Petrolacosaurus'', the possibly aquatic '' Spinoaequalis'', and less well-known genera such as ''Kadaliosaurus'' and '' Zarcasaurus''. This clade is usually considered to be the sister group to all (currently known) later diapsids. Description Araeoscelidians were small animals (less than one meter in length) looking somewhat like lizards, though they are only distantly related to true lizards. They differ from other, earlier sauropsids by their slender limbs, their elongated tail, and of course by the presence of two temporal openings, the feature defining the diapsid condition. In '' Araeoscelis'', only the upper temporal opening remains, thus resulting in a derived euryapsid condition. Genera Araeoscelidia includes well-know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropterygia
Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic diapsid 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, when they became extinct as part of the end-Cretaceous mass extinction. 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. Other than being diapsids, their affinities to other reptiles have long been contentious. Sometimes suggested to be closely related to turtles, other proposals have considered them most closely related to Lepidosauromorpha or Archosauromorpha, and/or the marine reptile groups Thalattosauria and Ichthyosauromorpha. Origins an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
