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Aphanosauria
Aphanosauria ("hidden lizards") is an extinct group of reptiles distantly related to dinosaurs (including birds). They are at the base of a group known as Avemetatarsalia, one of two main branches of archosaurs. The other main branch, Pseudosuchia, includes modern crocodilians. Aphanosaurs possessed features from both groups, indicating that they are the oldest and most primitive known clade of avemetatarsalians, at least in terms of their position on the archosaur family tree. Other avemetatarsalians include the flying pterosaurs, small bipedal Lagerpetidae, lagerpetids, herbivorous Silesauridae, silesaurids, and the incredibly diverse dinosaurs, which survive to the present day in the form of birds. Aphanosauria is formally defined as the most inclusive clade containing ''Teleocrater, Teleocrater rhadinus'' and ''Yarasuchus, Yarasuchus deccanensis'' but not ''House sparrow, Passer domesticus'' (house sparrow) or ''Nile crocodile, Crocodylus niloticus'' (Nile crocodile). This grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleocrater Vertebrae
''Teleocrater'' (meaning "completed basin", in reference to its closed acetabulum) is a genus of avemetatarsalian archosaur from the Middle Triassic Manda Formation of Tanzania. The name was coined by English paleontologist Alan Charig in his 1956 doctoral dissertation, but was only formally published in 2017 by Sterling Nesbitt and colleagues. The genus contains the type and only species ''T. rhadinus''. Uncertainty over the affinities of ''Teleocrater'' have persisted since Charig's initial publication; they were not resolved until Nesbitt ''et al.'' performed a phylogenetic analysis. They found that ''Teleocrater'' is most closely related to the similarly enigmatic ''Yarasuchus'', ''Dongusuchus'', and ''Spondylosoma'' in a group that was named the Aphanosauria. Aphanosauria was found to be the sister group of the Ornithodira, the group containing dinosaurs and pterosaurs. A carnivorous quadruped measuring long, ''Teleocrater'' is notable for its unusually long neck vertebrae. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yarasuchus
''Yarasuchus'' (meaning "red crocodile") is an extinct genus of avemetatarsalian archosaur that lived during the Anisian stage of the Middle Triassic of India.Bandyopadhyay, S. and Sengupta, D. P. (1999). Middle Triassic vertebrate faunas from India. ''Journal of African Earth Sciences'' 29: 233–241. The genus was named and described in 2005 from a collection of disarticulated but fairly complete fossil material found from the Middle Triassic Yerrapalli Formation. The material is thought to be from two individuals, possibly three, with one being much more complete and articulated than the other. The type and only species is ''Y. deccanensis''. ''Yarasuchus'' was a quadruped roughly long, with an elongated neck and tall spines on its vertebrae. Unlike other quadrupedal Triassic reptiles, the limbs and shoulders of ''Yarasuchus'' were slender, and more like those of ornithodirans. ''Yarasuchus'' has had a complicated taxonomic history, after originally being described as a " pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleocrater
''Teleocrater'' (meaning "completed basin", in reference to its closed acetabulum) is a genus of avemetatarsalian archosaur from the Middle Triassic Manda Formation of Tanzania. The name was coined by English paleontologist Alan Charig in his 1956 doctoral dissertation, but was only formally published in 2017 by Sterling Nesbitt and colleagues. The genus contains the type and only species ''T. rhadinus''. Uncertainty over the affinities of ''Teleocrater'' have persisted since Charig's initial publication; they were not resolved until Nesbitt ''et al.'' performed a phylogenetic analysis. They found that ''Teleocrater'' is most closely related to the similarly enigmatic '' Yarasuchus'', '' Dongusuchus'', and '' Spondylosoma'' in a group that was named the Aphanosauria. Aphanosauria was found to be the sister group of the Ornithodira, the group containing dinosaurs and pterosaurs. A carnivorous quadruped measuring long, ''Teleocrater'' is notable for its unusually long neck vert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avemetatarsalia
Avemetatarsalia (meaning "bird metatarsals") is a clade of diapsid Reptile, reptiles containing all archosaurs more closely related to birds than to crocodilians. The two most successful groups of avemetatarsalians were the dinosaurs and pterosaurs. Dinosaur, Dinosaurs were the largest terrestrial animals for much of the Mesozoic era, Mesozoic Era, and one group of small feathered dinosaurs (Aves, i.e. birds) has survived up to the present day. Pterosaur, Pterosaurs were the first flying vertebrates and persisted through the Mesozoic before dying out at the Cretaceous–Paleogene extinction event, Cretaceous-Paleogene (K-Pg) extinction event. Both dinosaurs and pterosaurs appeared in the Triassic period, Triassic Period, shortly after avemetatarsalians as a whole. The name Avemetatarsalia was first established by British palaeontologist Michael J. Benton, Michael Benton in 1999. An alternate name is Pan-Aves, or "all birds", in reference to its definition containing all animals, li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spondylosoma
''Spondylosoma'' (meaning "vertebra body") is a genus of avemetatarsalian archosaur belonging to the clade Aphanosauria from the late Ladinian-age Middle Triassic Lower Santa Maria Formation in Paleorrota Geopark, Brazil. History Friedrich von Huene based the genus on a fragmentary postcranial skeleton held at the University of Tübingen. This skeleton includes two teeth, two cervical vertebrae, four dorsal vertebrae, three sacral vertebrae, scapulae, part of a humerus, part of a femur, and part of a pubis. At the time, he thought it was a prosauropod.von Huene, F. (1942). ''Die fossilen Reptilien des südamerikanischen Gondwanalandes.'' C.H. Beck:Munich, 342 p. erman/ref> With the discovery of the basal dinosaur '' Staurikosaurus'', ''Spondylosoma'' drew attention as a possible relative. Authors went back and forth on the question, considering it either as a basal dinosaur, or as a " thecodont" or other basal archosaur. In 2000, Peter Galton noted that it lacks dinosauri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagerpetidae
Lagerpetidae (; originally Lagerpetonidae) is a family of basal avemetatarsalians (early-diverging members of the reptile lineage leading to birds and other dinosaurs). Though traditionally considered the earliest-diverging dinosauromorphs (archosaurs closer to dinosaurs than to pterosaurs), fossils described in 2020 suggested that lagerpetids are instead an early branch of pterosauromorphs (closer to pterosaurs than to dinosaurs). Lagerpetid fossils are known from the Triassic of San Juan (Argentina), Arizona, New Mexico, and Texas (United States), Rio Grande do Sul (Brazil), and Madagascar. ''Scleromochlus'', a minuscule archosaur from Scotland, is sometimes regarded as a lagerpetid or close relative of the family. Lagerpetids were generally small and lightly-built animals; the largest include '' Dromomeron gigas'' (from Argentina) and an indeterminate ''Dromomeron'' specimen from the Santa Rosa Formation of Texas, reaching a femoral length of . Lagerpetid fossils are rare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosaur
Archosauria () or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only extant taxon, extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistics, cladistic sense of the term includes all living and extinct relatives of birds and crocodilians such as non-avian dinosaurs, pterosaurs, phytosaurs, aetosaurs and rauisuchians as well as many marine reptile#Extinct groups, Mesozoic marine reptiles. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives; and Avemetatarsalia, which includes birds and their extinct relatives (such as non-avian dinosaurs and pterosaurs). Older definitions of the group Archosauria rely on shared morphology (biology), morphological ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asilisaurus
''Asilisaurus'' ( ); from Swahili, ''asili'' ("ancestor" or "foundation"), and Greek, (, "lizard") is an extinct genus of silesaurid archosaur. The type species is ''Asilisaurus kongwe''. ''Asilisaurus'' fossils were uncovered in the Manda Beds of Tanzania, a formation typically dated to the Anisian; however, some authors controversially assert that the formation may be early Carnian instead. If it truly is Anisian, ''Asilisaurus'' would be one of the oldest known members of the Avemetatarsalia (animals on the dinosaur/pterosaur side of the archosaurian family tree). It was the first non-dinosaurian dinosauriform recovered from Africa. The discovery of ''Asilisaurus'' has provided evidence for a rapid diversification of avemetatarsalians during the Middle Triassic, with the diversification of archosaurs during this time previously only documented in pseudosuchians ( crocodylian-line archosaurs). ''Asilisaurus'' is known from a relatively large amount of fossils compared to mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrate Bone
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids ( reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper part of the jaw joint. The lower jaw articulates at the articular bone, located at the rear end of the lower jaw. The quadrate bone forms the lower jaw articulation in all classes except mammals. Evolutionarily, it is derived from the hindmost part of the primitive cartilaginous upper jaw. Function in reptiles In certain extinct reptiles, the variation and stability of the morphology of the quadrate bone has helped paleontologists in the species-level taxonomy and identification of mosasaur squamates and spinosaurine dinosaurs. In some lizards and dinosaurs, the quadrate is articulated at both ends and movable. In snakes, the quadrate bone has become elongated and very mobile, and contributes greatly to their ability to swallow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxilla
In vertebrates, the maxilla (: maxillae ) 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. Anatomy Structure The maxilla is a paired bone - the two maxillae unite with each other at the intermaxillary suture. The maxilla consists of: * The body of the maxilla: pyramid-shaped; has an orbital, a nasal, an infratemporal, and a facial surface; contains the maxillary sinus. * Four processes: ** the zygomatic process ** the frontal process ** the alveolar process ** the palatine process It has three surfaces: * the anterior, posterior, medial Features of the maxilla include: * t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontal Bone
In the human skull, the frontal bone or sincipital bone is an unpaired bone which consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, part of the bony orbital cavity holding the eye, and part of the bony part of the nose respectively. The name comes from the Latin word ''frons'' (meaning "forehead"). Structure The frontal bone is made up of two main parts. These are the squamous part, and the orbital part. The squamous part marks the vertical, flat, and also the biggest part, and the main region of the forehead. The orbital part is the horizontal and second biggest region of the frontal bone. It enters into the formation of the roofs of the orbital and nasal cavities. Sometimes a third part is included as the nasal part of the frontal bone, and sometimes this is included with the squamous part. The nasal part is between the brow ridges, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
