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Neodiapsids
Neodiapsida is a clade, or major branch, of the reptilian family tree, typically defined as including all diapsids apart from some early primitive types known as the araeoscelidians. Modern reptiles and birds belong to the neodiapsid subclade Sauria. The oldest known neodiapsid is generally considered to be ''Orovenator'' from the Early Permian (Cisuralian) of North America. Basal-non saurian neodiaspids were ancestrally lizard-like, but basal Permian neodiapsids also include specialised swimming forms (''Hovasaurus'') the gliding lizard-like Weigeltisauridae, as well as the Triassic chameleon-like drepanosaurs. The position of the highly derived Mesozoic marine reptile groups Thalattosauria, Ichthyosauromorpha and Sauropterygia within Neodiapsida is uncertain, and they may lie within Sauria. Classification The clade Neodiapsida was given a phylogenetic definition by Laurin in 1991. He defined it as the branch-based clade containing all animals more closely related to "Youngin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saurosternon
''Saurosternon'' is an extinct genus of neodiapsid reptile from the Late Permian of South Africa. It is based on a partial skeleton split between two slabs of sandstone from the ''Daptocephalus'' Assemblage Zone. ''Saurosternon'' was one of the earliest small lizard-like reptiles to be discovered in Permian deposits of the Karoo Supergroup, preceding later discoveries such as ''Paliguana'', ''Youngina'', '' Palaeagama'', and '' Lacertulus''. The skeleton is mostly complete, though missing the head. Most of the original bone had decayed away by the time the fossil was discovered, leaving perfect molds in the sandstone slabs. What little bone remained was removed with acid by museum preparators, and the specimen was cast with latex to reconstruct the original bone shape. The affinities of ''Saurosternon'' are uncertain. Several studies interpreted it as one of the earliest lepidosauromorphs, the reptile group including squamates (lizards and snakes), rhynchocephalians (tuatara a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avicephala
Avicephala ("bird heads") is an extinct, potentially polyphyletic grouping of 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 unnatural grouping. However, the clade was recovered again in 2021 in a redescription of ''Weigeltisaurus'', raising the possibility that the clade may be valid after all. 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 ''Avicranium'' which possess toothless beaks, forward-facing eyes and large, rounded craniums. These superficial si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisuralian
The Cisuralian is the first Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian (geology), Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Mya. The Cisuralian is often synonymous with the informal terms early Permian or lower Permian. It corresponds approximately with the Wolfcampian in southwestern North America. The series saw the appearance of beetles and Fly, flies and was a relatively stable warming period of about 21 million years. Name and background The Cisuralian is the first series or epoch of the Permian. The Cisuralian was preceded by the last Pennsylvanian epoch (Gzhelian) and is followed by the Permian Guadalupian Epoch. The name "Cisuralian" was proposed in 1982, and approved by the International Subcommission on Permian Stratigraphy in 1996. The Ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosauromorpha
The Ichthyosauromorpha are an extinct clade of marine reptiles consisting of the Ichthyosauriformes and the Hupehsuchia, living during the Mesozoic. The node clade Ichthyosauromorpha was first defined by Ryosuke Motani ''et al.'' in 2014 as the group consisting of the last common ancestor of ''Ichthyosaurus communis'' and ''Hupehsuchus nanchangensis'', and all its descendants. Their synapomorphies, unique derived traits, include: the presence of an anterior flange on the humerus and Radius (bone), radius; the lower end of the ulna being as wide as or wider than the upper end, the forelimb being as long as or longer than the hindlimb, the hand having at least three quarters of the length of the upper arm and lower arm combined, the fibula extending behind the level of the thighbone, and the transverse process of the vertebral neural arch being reduced or absent. The Ichthyosauromorpha probably originated in China during the upper Lower Triassic period, about 248 million years ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Youngina Capensis
''Youngina'' 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). ''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'' was described briefly in 1914. The "''Youngoides romeri''" specimen was first attributed to ''Youngina'', but later given its eponymous ... [...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] |
Gliding Lizard
''Draco'' is a genus of agamid lizards that are also known as flying lizards, flying dragons or gliding lizards. These lizards are capable of gliding flight via membranes that may be extended to create wings (patagia), formed by an enlarged set of ribs. They are arboreal insectivores. While not capable of powered flight they often obtain lift in the course of their gliding flights. Glides as long as have been recorded, over which the animal loses only in height, which is quite some distance, considering that one lizard is only around in total length, tail included. Piper, Ross (2007). 'Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals'. Santa Barbara, California: Greenwood Press. They are found across Southeast Asia and southern India. and are fairly common in forests, areca gardens, teak plantations and shrub jungle. History of discovery Carl Linnaeus described the genus in 1758, with the type species being ''Draco volans.'' The name of the genus is from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hovasaurus
''Hovasaurus'' is an extinct genus of diapsid reptile belonging to the order Eosuchia. It lived in what is now Madagascar during the Late Permian and Early Triassic, being a survivor of the Permian–Triassic extinction event and the paleontologically youngest member of the Tangasauridae. Fossils have been found in the Permian Lower and Triassic Middle Sakamena Formations of the Sakamena Group, where it is amongst the commonest fossils. Its morphology suggests an aquatic ecology. Description ''Hovasaurus'' resembled a slender lizard, two thirds of total length was taken up by its long tail. It had snout-vent length up to long, with long tail. It was well adapted to an aquatic life, with the tail being laterally flattened like that of a sea snake. Some stones have been found in the abdomen of fossil ''Hovasaurus'', indicating the creatures swallowed these for ballast, preventing them from floating to the surface when hunting fish. Paleoenvironment The Lower Sakamamena F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araeoscelidia
Araeoscelidia or Araeoscelida is a clade of extinct 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 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-known genera such as ''Araeoscelis'' Williston 1910, '' ... [...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 tradition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between organisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauria
Sauria is the clade containing the most recent common ancestor of archosaurs (such as crocodilians, dinosaurs, etc.) and lepidosaurs ( lizards and kin), and all its descendants. Since most molecular phylogenies recover turtles as more closely related to archosaurs than to lepidosaurs as part of Archelosauria, Sauria can be considered the crown group of diapsids, or reptiles in general. Depending on the systematics, Sauria includes all modern reptiles or most of them (including birds, a type of archosaur) as well as various extinct groups. Sauria lies within the larger total group Sauropsida, which also contains various stem-reptiles which are more closely related to reptiles than to mammals. Prior to its modern usage, "Sauria" was used as a name for the suborder occupied by lizards, which before 1800 were considered crocodilians. Systematics Recent genomic studiesCrawford, Nicholas G., et al. "More than 1000 ultraconserved elements provide evidence that turtles are the sister g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
