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Clevosaurs
Clevosaurs are an extinct group of rhynchocephalian reptiles from the Triassic and Jurassic periods. History and definition Although members of this group have been known since 1910, only recently has the group received a formal name. In the late 1990s, Victor-Hugo Reynoso established that three particular genera of Sphenodontia (''Clevosaurus, Brachyrhinodon'', and ''Polysphenodon'') were closely related to each other. He gave the informal name "clevosaurs" to these three genera, after the most numerous and well-known genus, ''Clevosaurus.'' He considered clevosaurs to be members of the family Sphenodontidae, the family of rhynchocephalians containing the only living member of the order, the tuatara (''Sphenodon).'' In 2006, Bonaparte and Sues finally gave "clevosaurs" a formal name and taxonomic rank as the family Clevosauridae. They defined Clevosauridae as the last common ancestor of ''Clevosaurus, Brachyrhinodon,'' and ''Polysphenodon,'' and all of its descendants. In 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clevosauridae
Clevosaurs are an extinct group of rhynchocephalian reptiles from the Triassic and Jurassic periods. History and definition Although members of this group have been known since 1910, only recently has the group received a formal name. In the late 1990s, Victor-Hugo Reynoso established that three particular genera of Sphenodontia (''Clevosaurus, Brachyrhinodon'', and ''Polysphenodon'') were closely related to each other. He gave the informal name "clevosaurs" to these three genera, after the most numerous and well-known genus, ''Clevosaurus.'' He considered clevosaurs to be members of the family Sphenodontidae, the family of rhynchocephalians containing the only living member of the order, the tuatara (''Sphenodon).'' In 2006, Bonaparte and Sues finally gave "clevosaurs" a formal name and taxonomic rank as the family Clevosauridae. They defined Clevosauridae as the last common ancestor of ''Clevosaurus, Brachyrhinodon,'' and ''Polysphenodon,'' and all of its descendants. In 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clevosaurus
''Clevosaurus'' (meaning "Gloucester lizard") is an extinct genus of rhynchocephalian reptile from the Late Triassic and the Early Jurassic periods. Species of ''Clevosaurus'' were widespread across Pangaea, and have been found on all continents except Australia and Antarctica. Five species of ''Clevosaurus'' have been found in ancient fissure fill deposits in south-west England and Wales, alongside other sphenodontians, early mammals and dinosaurs. In regards to its Pangaean distribution, ''C. hadroprodon'' is the oldest record of a sphenodontian from Gondwana, though its affinity to ''Clevosaurus'' has been questioned. History of discovery The first species of ''Clevosaurus'' to be described was ''C. hudsoni'', which was described by William Elgin Swinton in 1939 from a fissure fill deposit in Cromhall Quarry ( Magnesian Conglomerate Formation) in the county of Gloucestershire, England, with the name of the county lending its name to the genus. Description ''Clevosaurus' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uromastyx Nigriventris - Uromastyx Acanthinurus Nigriventris - Ménagerie Paris 05
''Uromastyx'' is a genus of African and Asian agamid lizards, the member species of which are commonly called spiny-tailed lizards, uromastyces, mastigures, or dabb lizards. Lizards in the genus ''Uromastyx'' are primarily herbivorous, but occasionally eat insects and other small animals, especially young lizards. They spend most of their waking hours basking in the sun, hiding in underground chambers at daytime, or when danger appears. They tend to establish themselves in hilly, rocky areas with good shelter and accessible vegetation. Taxonomy The generic name (''Uromastyx'') is derived from the Ancient Greek words ''ourá'' (οὐρά) meaning "tail" and ''-mastix'' (μάστιξ) meaning "whip" or "scourge", after the thick-spiked tail characteristic of all ''Uromastyx'' species. Species The following species are in the genus ''Uromastyx''.. www.reptile-database.org. Three additional species were formerly placed in this genus, but have been moved to their own genu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Taxon
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachyrhinodon Taylori
''Brachyrhinodon'' (meaning "short nose tooth") is an extinct genus of sphenodontian from the Late Triassic Lossiemouth Sandstone of Scotland. It is related to the tuatara, the only member of its order that is not extinct. ''Brachyrhinodon'' is known from the sandstone quarries near Elgin, and is one of the Elgin Reptiles. Sources * ''Vertebrate Palaeontology'' by Michael J. Benton * ''In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods'' by Nicholas C. Fraser and Hans-Dieter Sues Hans-Dieter Sues (born January 13, 1956) is a German-born American paleontologist who is Senior Scientist and Curator of Vertebrate Paleontology at the National Museum of Natural History of the Smithsonian Institution in Washington, DC. He receiv ... *''The Beginning of the Age of Dinosaurs: Faunal Change across the Triassic-Jurassic Boundary'' by Kevin Padian Triassic lepidosaurs Triassic reptiles of Europe Sphenodontia Prehistoric reptile genera {{triassic-reptile-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Analysis
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 n ... [...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 ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia although some lizards are more closely related to these two excluded groups than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3-meter-long Komodo dragon. Most lizards are quadrupedal, running with a strong side-to-side motion. Some lineages (known as "legless lizards"), have secondarily lost their legs, and have long snake-like bodies. Some such as the forest-dwelling ''Draco'' lizards are able to glide. They are often territorial, the males fighting off other males and signalling, often with bright colours, to attract mates and to intimidate rivals. Lizards are mainly carnivorous, often being sit-and-wait predators; many smaller species eat insects, while the Komodo eats mammals a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uromastyx
''Uromastyx'' is a genus of African and Asian agamid lizards, the member species of which are commonly called spiny-tailed lizards, uromastyces, mastigures, or dabb lizards. Lizards in the genus ''Uromastyx'' are primarily herbivorous, but occasionally eat insects and other small animals, especially young lizards. They spend most of their waking hours basking in the sun, hiding in underground chambers at daytime, or when danger appears. They tend to establish themselves in hilly, rocky areas with good shelter and accessible vegetation. Taxonomy The generic name (''Uromastyx'') is derived from the Ancient Greek words ''ourá'' (οὐρά) meaning "tail" and ''-mastix'' (μάστιξ) meaning "whip" or "scourge", after the thick-spiked tail characteristic of all ''Uromastyx'' species. Species The following species are in the genus ''Uromastyx''.. www.reptile-database.org. Three additional species were formerly placed in this genus, but have been moved to their own genu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palatine Bone
In anatomy, the palatine bones () are two irregular bones of the facial skeleton in many animal species, located above the uvula in the throat. Together with the maxillae, they comprise the hard palate. (''Palate'' is derived from the Latin ''palatum''.) Structure The palatine bones are situated at the back of the nasal cavity between the maxilla and the pterygoid process of the sphenoid bone. They contribute to the walls of three cavities: the floor and lateral walls of the nasal cavity, the roof of the mouth, and the floor of the orbits. They help to form the pterygopalatine and pterygoid fossae, and the inferior orbital fissures. Each palatine bone somewhat resembles the letter L, and consists of a horizontal plate, a perpendicular plate, and three projecting processes—the pyramidal process, which is directed backward and lateral from the junction of the two parts, and the orbital and sphenoidal processes, which surmount the vertical part, and are separated by a dee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygoid Bone
The pterygoid is a paired bone forming part of the palate of many vertebrates, behind the palatine bone In anatomy, the palatine bones () are two irregular bones of the facial skeleton in many animal species, located above the uvula in the throat. Together with the maxillae, they comprise the hard palate. (''Palate'' is derived from the Latin ''pa ...s. It is a flat and thin lamina, united to the medial side of the pterygoid process of the sphenoid bone, and to the perpendicular lamina of the palatine bone. Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxilla
The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible (lower jaw), which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw. Structure In humans, the maxilla consists of: * The body of the maxilla * Four processes ** the zygomatic process ** the frontal process of maxilla ** the alveolar process ** the palatine process * three surfaces – anterior, posterior, medial * the Infraorbital foramen * the maxillary sinus * the incisive foramen Articulations Each maxilla articulates with nine bones: * two of the cranium: the frontal and ethmoid * seven of the face: the nasal, zygomatic, lacrimal, inferior n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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