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Progalesaurus
''Progalesaurus'' is an extinct genus of galesaurid cynodont from the early Triassic. ''Progalesaurus'' is known from a single fossil of the species ''Progalesaurus lootsbergensis'', found in the ''Lystrosaurus'' Assemblage Zone of the Balfour Formation. Close relatives of ''Progalesaurus,'' other galesaurids, include ''Galesaurus'' and '' Cynosaurus''. Galesaurids appeared just before the Permian-Triassic extinction event, and disappeared from the fossil record in the Middle-Triassic. The name “Progalesaurus” is derived from Greek, “pro” meaning before, “gale” meaning weasel or cat, and “saurus” meaning lizard or reptile (Sidor and Smith). The name refers to the relationship ''Progalesaurus'' has to the more derived ''Galesaurus.'' Discovery and history ''Progalesaurus'' was originally discovered by Roger M. H. Smith in 1998. The specimen was found in the Sneeuberg mountains near New Lootsberg Pass in the Karoo Basin of South Africa. ''Progalesaurus'' was fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christian Sidor
Christian Alfred Sidor is an American vertebrate paleontologist. He is currently a Professor in the Department of Biology, University of Washington in Seattle, as well as Curator of Vertebrate Paleontology and Associate Director for Research and Collections at the Burke Museum of Natural History and Culture. His research focuses on Permian and Triassic tetrapod evolution, especially on therapsids. Academic and professional background Sidor received a B.S. (with honors) in biology from Trinity College in 1994. He went on to pursue his graduate studies at the University of Chicago, completing his M.S. in 1996 and his Ph.D. in 2000 under the supervision of James Hopson. Sidor won the Romer Prize in 2001 for his doctoral work, a competitive annual award at the Society of Vertebrate Paleontology annual meeting for the best predoctoral student oral presentation. Following his dissertation, Sidor held a postdoctoral fellowship at the National Museum of Natural History (2001) before bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galesaurus
''Galesaurus'' (from the Greek roots for 'weasel' and 'lizard') is an extinct genus of carnivorous cynodont therapsid that lived between the Induan and the Olenekian stages of the Early Triassic in what is now South Africa. It was incorrectly classified as a dinosaur by Sir Richard Owen in 1859. Notably, ''Galesaurus'' was mentioned in the first issue of Nature in 1869, where T. H. Huxley erroneously expressed confidence that it would eventually be shown to be a dinosaur. Description The largest ''Galesaurus'' skull discovered is roughly long. Larger remains indicate that an adult ''Galesaurus'' is roughly long. Cynodonts, including ''Galesaurus,'' are believed to have had sprawling postures. Examination of ''Galesaurus'' reveals two distinct morphs, a gracile and a robust morph. The main differences between the two morphs lie in the pectoral and pelvic girdles, as well as subtle differences in the fore and hind limbs. The morphological differences may be due to sexual dimo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galesauridae
Galesauridae is an extinct family of cynodonts. Along with the family Thrinaxodontidae and the extensive clade Eucynodontia (which includes mammals), it makes up the unranked taxon called Epicynodontia. Galesaurids first appeared in the very latest Permian period, just a million years (or perhaps only a thousand years) before the greatest extinction of all time, the Permian-Triassic extinction event. Galesaurids are some of the most primitive of the Epicynodontia. They may have resembled basal cynodonts such as the Procynosuchidae, and they may have descended from a Procynosuchid-like ancestor, but the Galesaurids were more advanced than the basal Cynodontia. It is clear that, like many other Epicynodontians, many Galesaurids had a complete secondary palate, which allowed them to swallow food while breathing, and the dentary bone was enlarged relative to those of their ancestors. Their temporal fenestrae are much larger than those of the Procynosuchids, but not as large as in m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrinaxodon
''Thrinaxodon'' is an extinct genus of cynodonts, most commonly regarded by its species ''T. liorhinus'' which lived in what are now South Africa and Antarctica during the Early Triassic. ''Thrinaxodon'' lived just after the Permian–Triassic mass extinction event, its survival during the extinction may have been due to its burrowing habits. Similar to other therapsids, ''Thrinaxodon'' adopted a semi-sprawling posture, an intermediary form between the sprawling position of basal tetrapods (still observed modern Crocodilia) and the more upright posture present in current mammals.Blob R. 2001. Evolution of hindlimb posture in non-mammalian therapsids: biomechanical tests of paleontological hypotheses. 27(1): 14-38. ''Thrinaxodon'' is prevalent in the fossil record in part because it was one of the few carnivores of its time, and was of a larger size than similar cynodont carnivores. Description ''Thrinaxodon'' was a small synapsid roughly the size of a fox and possibly covered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicynodontia
Epicynodontia is a clade of cynodont therapsids that includes most cynodonts, such as galesaurids, thrinaxodontids, and Eucynodontia (including mammals). It was erected as a stem-based taxon by Hopson and Kitching (2001) and defined as the most inclusive clade containing Mammalia and excluding ''Procynosuchus'', a Late Permian genus that is one of the most basal cynodonts. Below is a 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 ... from Ruta, Botha-Brink, Mitchell and Benton (2013) showing one hypothesis of cynodont relationships: References Cynodonts Lopingian first appearances Extant Permian first appearances Tetrapod unranked clades Taxa named by James Hopson Taxa named by James Kitching {{Therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynosaurus
''Cynosaurus'' is an extinct genus of cynodonts. Remains have been found from the ''Dicynodon'' Assemblage Zone in South Africa.T. S. Kemp: ''The Origin and Evolution of Mammals'' Oxford University Press, 2005. ''Cynosaurus'' was first described by Richard Owen in 1876 as ''Cynosuchus suppostus''. ''Cynosaurus'' has been found in the late Permian period. Cyno- is derived from the Greek word kyon for dog and –sauros in Greek meaning lizard. Paleoenvironment Fossils of ''Cynosaurus'' have been found in the ''Cistecephalus'' and ''Daptocephalus'' Assemblage Zones, in the Balfour Formation of the Beaufort Group, pertaining to the Karoo Supergroup of South Africa. In the Karoo Basin of South Africa riverbanks would be over flooded creating floodplains that could hold all that water to start soil accumulation.Viglietti et al, 2018 In the lower Balfour Formation, the soil deposits suggest a lacustrine environment with abundant leaf impressions (Viglietti et al., 2018). This sugg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynodont
The cynodonts () (clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variety of lifestyles, including carnivory and herbivory. Mammals are cynodonts, as are their extinct ancestors and close relatives, having evolved from advanced probainognathian cynodonts during the Late Triassic. All other cynodont lines went extinct, with the last known non-mammalian cynodont group, the Tritylodontidae, having its youngest records in the Early Cretaceous. Description Early cynodonts have many of the skeletal characteristics of mammals. The teeth were fully differentiated and the braincase bulged at the back of the head. Outside of some crown-group mammals (notably the therians), all cynodonts probably laid eggs. The temporal fenestrae were much larger than those of their ancestors, and the widening of the zygomatic arch in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynodont
The cynodonts () (clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variety of lifestyles, including carnivory and herbivory. Mammals are cynodonts, as are their extinct ancestors and close relatives, having evolved from advanced probainognathian cynodonts during the Late Triassic. All other cynodont lines went extinct, with the last known non-mammalian cynodont group, the Tritylodontidae, having its youngest records in the Early Cretaceous. Description Early cynodonts have many of the skeletal characteristics of mammals. The teeth were fully differentiated and the braincase bulged at the back of the head. Outside of some crown-group mammals (notably the therians), all cynodonts probably laid eggs. The temporal fenestrae were much larger than those of their ancestors, and the widening of the zygomatic arch in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynognathia
Cynognathia ("dog jaw") is one of two major clades of cynodonts, the other being Probainognathia. Cynognathians included the large carnivorous genus ''Cynognathus'' and the herbivorous traversodontids. Cynognathians can be identified by several synapomorphies including a very deep zygomatic arch that extends above the middle of the orbit. Cynognathian fossils are currently known from Africa, Antarctica, Asia, Europe, North America and South America. Taxonomy *Suborder Cynodontia **Infraorder Eucynodontia ***(unranked) Cynognathia ****Family Cynognathidae *****''Cynognathus'' ****(unranked) Gomphodontia *****Family Diademodontidae ******''Diademodon'' ******'' Titanogomphodon'' *****(unranked) Neogomphodontia ******Family Trirachodontidae *******Subfamily Trirachodontinae ********''Langbergia'' ********'' Trirachodon'' *******Subfamily Sinognathinae ********''Beishanodon'' ********'' Sinognathus'' ********''Cricodon'' ******Family Traversodontidae *******'' Etjoia'' *******'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eucynodontia
Eucynodontia ("true dog teeth") is a clade of cynodont therapsids including mammals and most non-mammalian cynodonts. The oldest eucynodonts are known from the Early Triassic and possibly Late Permian. Eucynodontia includes two major subgroups, Cynognathia and Probainognathia. The clade was named in 1982 by Thomas Kemp, who defined it as all cynodonts more derived than ''Thrinaxodon''. In 2001, Hopson and Kitching redefined the clade Eucynodontia as the least inclusive group containing Mammalia and ''Exaeretodon ''Exaeretodon'' is an extinct genus of fairly large, low-slung traversodontid cynodonts from the southern parts of Pangea. Four species are known, from various formations. ''E. argentinus'' is from the Carnian-age (Late Triassic) Cancha de Boch ...''.James A. Hopson and James W. Kitching, 2001, "A Probainognathian Cynodont from South Africa and the Phylogeny of Nonmammalian Cynodonts" pp 5-35 in: PARISH A. JENKINS, JR., MICHAEL D. SHAPIRO, AND TOMASZ OWERKOWICZ, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probainognathia
Probainognathia is one of the two major subgroups of the clade Eucynodontia, the other being Cynognathia. The earliest forms were carnivorous and insectivorous, though some groups eventually also evolved herbivorous diets. The earliest and most basal probainognathian is the Middle Triassic (Anisian) aged ''Lumkuia'', from South Africa, though probainognathians would not become prominent until the mid Norian stage of the Late Triassic. Three groups survived the extinction at the end of Triassic: Tritheledontidae and Tritylodontidae, which both survived until the Jurassic—the latter even into the Cretaceous (''Montirictus'' and '' Xenocretosuchus'')—and Mammaliaformes, which includes the mammals. Phylogeny Below is a cladogram from Ruta, Botha-Brink, Mitchell and Benton (2013) showing one hypothesis of cynodont relationships: See also * Evolution of mammals * List of prehistoric mammals This is an incomplete list of prehistoric mammals. It does not include extant mam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platycraniellus
''Platycraniellus'' is an extinct genus of non-mammalian cynodonts. It is known from the Early Triassic ''Lystrosaurus'' Assemblage Zone of the Normandien Formation of South Africa. The type and only species is ''P. elegans''. See also * List of therapsids This list of therapsids is an attempt to create a comprehensive listing of all genera that have ever been included in the Therapsida excluding mammals and purely vernacular terms. The list includes all commonly accepted genera, but also genera tha ... References Prehistoric cynodont genera Induan life Early Triassic synapsids of Africa Triassic South Africa Fossils of South Africa Fossil taxa described in 1917 Taxa named by Egbert Cornelis Nicolaas van Hoepen {{Paleo-Therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
