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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] |
Younginiformes
Younginiformes is a group of diapsid reptiles known from the Permian-Triassic of Africa and Madagascar. It has been used as a replacement for " Eosuchia". Younginiformes (including '' Acerosodontosaurus'', '' Hovasaurus'', '' Kenyasaurus'', '' Tangasaurus'', '' Thadeosaurus'' and ''Youngina'') were historically suggested to be lepidosauromorphs, but are currently thought to be basal non- saurian neodiapsids. The group is sometimes divided into two families, Tangasauridae and Younginidae. The monophyly of the group is disputed. A 2009 study found them to be an unresolved polytomy at the base of Neodiapsida, while a 2011 study recovered the group as paraphyletic. A 2022 study recovered the Younginiformes as a monophyletic group of basal neodiapsid reptiles, also including '' Claudiosaurus'' and '' Saurosternon'' as part of the group. Some younginiforms like ''Hovasaurus'' and ''Acerosodontosaurus'' are thought to have had an amphibious lifestyle, while others like ''Kenyasaurus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Youngina Capensis
''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 "''Youngoides romer ... [...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 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 s ... [...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] |
Eosuchia
Eosuchians are an extinct order of diapsid reptiles. Depending on which taxa are included the order may have ranged from the late Carboniferous to the Eocene but the consensus is that eosuchians are confined to the Permian and Triassic. Eosuchia was initially defined to include all "thecodontian" reptiles which did not have an antorbital fenestra but did retain tabulars, postparietals and a large pineal foramen (Broom, 1914). Broom coined the term as a new suborder for ''Youngina''. A definition for inclusion in the order is difficult: it is almost easier to list the primitively-diapsid reptiles that have not been included at one time or another. The order has almost been treated as a dustbin for diapsids that are not obviously lepidosaurian or archosaurian. One consequence has been Romer's suggestion of the alternative order Younginiformes to be applied strictly to those forms with the primitive diapsid form, in particular, a complete lowermost arch as the quadratojugal and j ... [...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] |
Heleosaurus
''Heleosaurus scholtzi'' is an extinct species of basal synapsids, known as pelycosaurs, in the family of Varanopidae during the middle Permian.Reisz, R. R. & Modesto, S. P. 2007. ''Heleosaurus scholtzi'' from the Permian of South Africa: a varanopid synapsid, not a diapsid reptile. ''Journal of Vertebrate Paleontology'' 27 (3): 734-739. At first ''H. scholtzi'' was mistakenly classified as a diapsid. Members of this family were carnivorous and had dermal armor, and somewhat resembled monitor lizards. This family was the most geologically long lived, widespread, and diverse group of early amniotes. To date only two fossils have been found in the rocks of South Africa.Broom, R. "On Some New Fossil Reptiles from the Karroo Beds of Victoria West, South Africa." ''Transactions of the South African Philosophical Society'' 18 (1907): 31-42. Taylor and Francis Online. Web. Botha-Brink, Jennifer. "A Mixed-Age Classed 'Pelycosaur' Aggregation from South Africa: Earliest Evidence of Parental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incertae Sedis
or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by (of uncertain family), (of uncertain suborder), (of uncertain order) and similar terms. Examples * The fossil plant ''Paradinandra, Paradinandra suecica'' could not be assigned to any family, but was placed ''incertae sedis'' within the order Ericales when described in 2001. * The fossil ''Gluteus minimus (fossil), Gluteus minimus'', described in 1975, could not be assigned to any known animal phylum. The genus is therefore ''incertae sedis'' within the kingdom Animalia. * While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves ''incertae sedis''. It was later agreed to place them in a separate order, Cathartiformes. * Boc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heleosuchus
''Heleosuchus'' is an extinct genus of diapsid reptile from the Late Permian of South Africa. It was originally described as a species of ''Saurosternon'' by Richard Owen. The type species is ''Saurosternon griesbachi''. The specific name honours Carl Ludolf Griesbach. It was later recognized as a separate genus by Robert Broom. At one time, the type specimen of ''Heleosuchus'' was thought to be lost. However, it remains at the Natural History Museum, Vienna, where it is numbered NHMW 2374, while the Natural History Museum (formerly British Museum (Natural History)) possesses a cast numbered R. 5000. Several other casts of NHMW 2374 are present in several other European institutions, among them a cast of higher fidelity to the original. While the type was thought to be lost, Susan E. Evans redescribed this taxon on the basis of an older mold which had been taken of the type specimen prior to its disappearance. When the specimen appeared in later years, a higher quality mold was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepidosauromorph
Lepidosauromorpha (in PhyloCode known as Pan-Lepidosauria) is a group of reptiles comprising all diapsids closer to lizards than to archosaurs (which include crocodiles and birds). The only living sub-group is the Lepidosauria, which contains two subdivisions, Squamata, which contains lizards and snakes, and Rhynchocephalia, the only extant species of which is the tuatara. Lepidosauromorphs are distinguishable from archosauromorphs (reptiles closer to archosaurs) by their primitive sprawling gait (allowing for the same sinusoidal trunk and tail movement seen in fish), the sliding "joint" between the coracoids and the sternum (for a longer stride), and their pleurodont dentition. In contrast, Archosauromorphs possess a parasagittal gait, a reduction in their dermal girdle, a reduction and/or loss of the sternum, and a more thecodont dentition. Living lepidosauromorphs have retained an ectothermic (" cold blooded") metabolism, unlike the ancestral condition in archosauromorphs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
