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Prozostrodontia
Prozostrodontia is a clade of cynodonts including mammaliaforms and their closest relatives such as Tritheledontidae and Tritylodontidae. It was erected as a node-based taxon by Liu and Olsen (2010) and defined as the least inclusive clade containing ''Prozostrodon brasiliensis'', '' Tritylodon langaevus'', '' Pachygenelus monus'', and ''Mus musculus'' (the house mouse). Prozostrodontia is diagnosed by several characters, including: * Reduced prefrontal and postorbital bones, with a reduction or disappearance of a strut of bone called the postorbital bar separating the eye socket from the temporal region * Unconnected dentary bones in the lower jaw * The presence of a small hole in the skull called the sphenopalatine foramen * A sagittal crest extending along the top of the skull and connecting with a lambdoidal crest at the back of the skull * Neural spines of the dorsal vertebrae angled backward * A convex-shaped iliac crest and a reduced posterior iliac spine on the hip * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alemoatherium
''Alemoatherium'' is an extinct genus of prozostrodontian cynodont which lived in the Late Triassic of Brazil. It contains a single species, ''A. huebneri'', named in 2017 by Agustín Martinelli and colleagues. The genus is based on UFSM 11579b, a left lower jaw (dentary) found in the Alemoa Member of the Santa Maria Formation, preserving the late Carnian-age ''Hyperodapedon'' Assemblage Zone. ''Alemoatherium'' was among the smallest species of cynodonts found in the rich synapsid fauna of the Santa Maria Formation. Its blade-like four-cusped postcanine teeth show many similarities with those of dromatheriids, an obscure group of early prozostrodontians. Description The dentary is similar in shape to that of many other prozostrodontians, with an overall slender form that abruptly changes angle near the front of the jaw. This distinct change in angle separates the dentary into two main regions, the horizontal ramus behind the level of the first postcanine tooth, and the upwards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therioherpeton
''Therioherpeton'' is an extinct genus of small, carnivorous cynodonts belonging to the clade Prozostrodontia, which lived in what is now Brazil during the Late Triassic. Its type species is ''Therioherpeton cargnini''. It was named in 1975 by the palaeontologists José Bonaparte and Mário Costa Barberena based on remains collected in the ''Hyperodapedon'' Assemblage Zone of the Santa Maria Formation in the Paraná Basin.''Therioherpeton'' site, Faixa Nova at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database
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Agudotherium
''Agudotherium'' is an extinct genus of prozostrodontian cynodonts from the Late Triassic Candelária Formation of the Paraná Basin in southern Brazil. The genus contains one species, ''Agudotherium gassenae''. ''A. gassenae'' is known from two specimens, both consisting of partial lower jaws with teeth. Etymology The generic name ''Agudotherium'' comes from the municipality of Agudo, Rio Grande do Sul Agudo is a municipality in Rio Grande do Sul, the southernmost state of Brazil. Location Agudo is 83 meters above sea level. The total area is 553,1 km² and the population was estimated at 16,401 in 2020. The municipality contains part of ..., where the fossils were discovered, and the Greek word (), meaning "beast". References Prehistoric prozostrodonts Prehistoric cynodont genera Norian genera Late Triassic synapsids of South America Triassic Brazil Fossils of Brazil Paraná Basin Fossil taxa described in 2020 {{Paleo-therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammaliamorpha
Mammaliamorpha is a clade of cynodonts. It contains the clades Tritylodontidae and Mammaliaformes, as well as a few genera that do not belong to either of these groups. The family Tritheledontidae has also been placed in Mammaliamorpha by some phylogenetic analyses, but has been recovered outside the clade by others. According to a 2022 study based on inner ear anatomy, Mammaliamorpha may be the clade in which endothermy ("warm-bloodedness") first appeared in the mammalian lineage. Classification Mammaliamorpha was named in 1988 by the American palaeontologist Timothy B. Rowe, who defined it as comprising "the last common ancestor of Tritylodontidae and Mammalia, and all its descendants". The 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 d ... below is adapted from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Fenestra
An infratemporal fenestra, also called the lateral temporal fenestra or simply temporal fenestra, is an opening in the skull behind the orbit in some animals. It is ventrally bordered by a zygomatic arch. An opening in front of the eye sockets, conversely, is called an antorbital fenestra. Both of these openings reduce the weight of the skull. Infratemporal fenestrae are commonly (although not universally) seen in the fossilized skulls of dinosaurs. Synapsids, including mammals, have one temporal fenestra, while sauropsids Sauropsida ("lizard faces") is a clade of amniotes, broadly equivalent to the class Reptilia. Sauropsida is the sister taxon to Synapsida, the other clade of amniotes which includes mammals as its only modern representatives. Although early sy ..., the birds and reptiles, have two. References {{ref list Dinosaur anatomy Foramina of the skull ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prefrontal Bone
The prefrontal bone is a bone separating the lacrimal and frontal bones in many tetrapod skulls. It first evolved in the sarcopterygian clade Rhipidistia, which includes lungfish and the Tetrapodomorpha. The prefrontal is found in most modern and extinct lungfish, amphibians and reptiles. The prefrontal is lost in early mammaliaforms and so is not present in modern mammals either. In dinosaurs The prefrontal bone is a very small bone near the top of the skull, which is lost in many groups of coelurosaurian theropod dinosaurs and is completely absent in their modern descendants, the birds. Conversely, a well developed prefrontal is considered to be a primitive feature in dinosaurs. The prefrontal makes contact with several other bones in the skull. The anterior part of the bone articulates with the nasal bone and the lacrimal bone. The posterior part of the bone articulates with the frontal bone and more rarely the palpebral bone The palpebral bone is a small dermal bone found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postorbital Bone
The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some vertebrates, the postorbital is fused with the postfrontal to create a postorbitofrontal. Birds have a separate postorbital as an embryo, but the bone fuses with the frontal Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * ''The Front'', 1976 film Music * The Front (band), an American rock band signed to Columbia Records and active in the 1980s and e ... before it hatches. References * Roemer, A. S. 1956. ''Osteology of the Reptiles''. University of Chicago Press. 772 pp. Skull {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postorbital Bar
The postorbital bar (or postorbital bone) is a bony arched structure that connects the frontal bone of the skull to the zygomatic arch, which runs laterally around the eye socket. It is a trait that only occurs in mammalian taxa, such as most strepsirrhine primates and the hyrax, while haplorhine primates have evolved fully enclosed sockets. One theory for this evolutionary difference is the relative importance of vision to both orders. As haplorrhines (tarsiers and simians) tend to be diurnal, and rely heavily on visual input, many strepsirrhines are nocturnal and have a decreased reliance on visual input. Postorbital bars evolved several times independently during mammalian evolution and the evolutionary histories of several other clades. Some species, such as Tarsiers, have a postorbital septum. This septum can be considered as joined processes with a small articulation between the frontal bone, the zygomatic bone and the alisphenoid bone and is therefore different from the posto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit (anatomy)
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is , of which the eye occupies . The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and duct, the eyelids, medial and lateral palpebral ligaments, cheek ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves. Structure The orbits are conical or four-sided pyramidal cavities, which open into the midline of the face and point back into the head. Each consists of a base, an apex and four walls."eye, human."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD 2009 Openings There are two important foramina, or windows, two important fissu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, Ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful sandstone'')'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentary Bone
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull (discounting the ossicles of the middle ear). It is connected to the temporal bones by the temporomandibular joints. The bone is formed in the fetus from a fusion of the left and right mandibular prominences, and the point where these sides join, the mandibular symphysis, is still visible as a faint ridge in the midline. Like other symphyses in the body, this is a midline articulation where the bones are joined by fibrocartilage, but this articulation fuses together in early childhood.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 59 The word "mandible" derives from the Latin word ''mandibula'', "jawbone" (literally "one used for chewing"), from '' mandere'' "to chew" and ''-bula'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachygenelus Monus
''Pachygenelus'' is an extinct genus of tritheledontid cynodonts. Fossils have been found from the Karoo basin in South Africa and date back to the Early Jurassic. ''Pachygenelus'' had both an articular- quadrate and dentary-squamosal jaw joint characteristic of ictidosaurs. Only mammals possess the dentary-squamosal articulation, while all other tetrapods possess the typical arcticular-quadrate articulation. Thus the jaw of ''Pachygenelus'' can be seen as transitional between non-mammalian synapsids and true mammals. Another feature of ''Pachygenelus'' that is shared with mammals is plesiomorphic prismatic enamel, or enamel arranged into strengthened prisms. The upper and lower tooth rows occluded with one another, although not as close as what is seen in true mammals. Wear facets are present on the lingual sides of the upper and external faces of the lower postcanines, and are seen as evidence for the occlusion. Despite all of the derived adaptation seen in its teeth, the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
