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Thrinaxodon
''Thrinaxodon'' is an extinct genus of cynodonts which lived in what are now South Africa and Antarctica during the Late Permian - Early Triassic. ''Thrinaxodon'' lived just before, during, and right after the Permian–Triassic mass extinction event. It is known from a single species, ''T. liorhinus''. Similar to other therapsids, ''Thrinaxodon'' adopted a semi-sprawling posture, an intermediary form between the sprawling position of basal tetrapods 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. Its survival during the Permian-Triassic extinction event may have been due to its burrowing habits. Description ''Thrinaxodon'' was a small synapsid roughly the size of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrinaxodon Liorhinus
''Thrinaxodon'' is an extinct genus (biology), genus of cynodonts which lived in what are now South Africa and Antarctica during the Late Permian - Early Triassic. ''Thrinaxodon'' lived just before, during, and right after the Permian–Triassic extinction event, Permian–Triassic mass extinction event. It is known from a single species, ''T. liorhinus''. Similar to other therapsids, ''Thrinaxodon'' adopted a semi-sprawling posture, an intermediary form between the sprawling position of basal tetrapods 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. Its survival during the Permian-Triassic extinction event may have been due to its burrowing habits. Description ''Thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrinaxodon BW
''Thrinaxodon'' is an extinct genus of cynodonts which lived in what are now South Africa and Antarctica during the Late Permian - Early Triassic. ''Thrinaxodon'' lived just before, during, and right after the Permian–Triassic mass extinction event. It is known from a single species, ''T. liorhinus''. Similar to other therapsids, ''Thrinaxodon'' adopted a semi-sprawling posture, an intermediary form between the sprawling position of basal tetrapods 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. Its survival during the Permian-Triassic extinction event may have been due to its burrowing habits. Description ''Thrinaxodon'' was a small synapsid roughly the size of a ... [...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 (journal), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynodont
Cynodontia () is a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 Megaannum, mya), and extensively diversified after the Permian–Triassic extinction event. Mammals are cynodonts, as are their extinct ancestors and close relatives (Mammaliaformes), having evolved from advanced probainognathian cynodonts during the Late Triassic. Non-mammalian cynodonts occupied a variety of ecological niches, both as carnivores and as herbivores. Following the emergence of mammals, most other cynodont lines went extinct, with the last known non-mammaliaform 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, crown-group mammals (notably the therians), all cynodonts probably laid eggs. The temporal fenestrae#Fenestra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lystrosaurus Assemblage Zone
The ''Lystrosaurus'' Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the upper Adelaide and lower Tarkastad Subgroups of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. This biozone has outcrops in the south central Eastern Cape ( Middelburg, Queenstown, Aliwal North, Nieu-Bethesda) and in the southern and northeastern Free State ( Bethulie, Gariep Dam, Mthatha, Harrismith). The ''Lystrosaurus'' Assemblage Zone is one of eight biozones found in the Beaufort Group, and is considered to be Early Triassic in age. The name of the biozone refers to ''Lystrosaurus'', a small to medium-sized dicynodont therapsid. It is characterized by the appearance of further ''Lystrosaurus'' subspecies which are confined to this biozone. '' Lystrosaurus maccaigi'' and ''Lystrosaurus curvatus'' are the only two species found outside the ''Lystrosaurus'' Assemblage Zone in Upper Permian deposits o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fremouw Formation
The Fremouw Formation is a Triassic-age rock formation in the Transantarctic Mountains of the Ross Depenency of Antarctica. It contains the oldest known fossils of tetrapods from Antarctica, including synapsids, reptiles and amphibians. Fossilized trees have also been found. The formation's beds were deposited along the banks of rivers and on floodplains. During the Triassic, the area would have been a riparian forest at 70–75°S latitude. Stratigraphy The Fremouw Formation is mostly Triassic in age, with the oldest rocks dating back to the latest Permian. Much of the formation is quartzose sandstone that was deposited in stream beds. It overlies the Permian Buckley Formation, which consists of coal and '' Glossopteris'' fossils. The formation is informally divided into lower, middle, and upper units. Most fossils are found in the Lower Fremouw Formation. Here, bones are preserved in fine-grained siltstones and mudstones, coarse-grained channel sandstones, and conglomerate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therapsids
Therapsida is a clade comprising a major group of eupelycosaurian synapsids that includes mammals and their ancestors and close relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more underneath the body, resulting in a more "standing" quadrupedal posture, as opposed to the lower sprawling posture of many reptiles and amphibians. Therapsids evolved from earlier synapsids commonly called "pelycosaurs", specifically within the Sphenacodontia, more than 279.5 million years ago. They replaced the pelycosaurs as the dominant large land animals in the Guadalupian through to the Early Triassic. In the aftermath of the Permian–Triassic extinction event, therapsids declined in relative importance to the rapidly diversifying archosaurian sauropsids (pseudosuchians, dinosaurs and pterosaurs, etc.) during the Middle Triassic. The therapsids include the cynodonts, the group that gave rise to mammals (M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normandien Formation
The Normandien Formation is a Triassic-age rock formation located in Free State, South Africa. It is where the fossils of Ericiolacerta, a subtaxa of Ericiolacertidae, were found. Fossil content Among others, these fossils were reported from the formation: at .org * '' Aenigmasaurus grallator'' * '' Broomistega putterilli'' * '' Ericiolacerta parva'' * '' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Katberg Formation
The Katberg Formation is a geological formation that is found in the Beaufort Group, a major geological group that forms part of the greater Karoo Supergroup in South Africa. The Katberg Formation is the lowermost geological formation of the Tarkastad Subgroup which contains the Lower to Middle Triassic-aged rocks of the Beaufort Group. Outcrops and exposures of the Katberg Formation are found east of 24 degrees onwards and north of Graaff-Reniet, Nieu Bethesda, Cradock, Fort Beaufort, Queensdown, and East London in the south, and ranges as far north as Harrismith in deposits that form a ring around the Drakensberg mountain ranges. Geology The Katberg Formation overlies the Balfour Formation of the Adelaide Subgroup and the Burgersdorp Formation of the upper Tarkastad Subgroup, all pertaining to the greater Beaufort Group. The appearance of the Katberg Formation rocks starkly differs from the underlying Balfour Formation due to its high sandstone content and reddish colo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beaufort Group
The Beaufort Group is the third of the main subdivisions of the Karoo Supergroup in South Africa. It is composed of a lower Adelaide Subgroup and an upper Tarkastad Subgroup. It follows conformably after the Ecca Group and unconformably underlies the Stormberg Group. Based on stratigraphic position, lithostratigraphic and biostratigraphic correlations, palynological analyses, and other means of geological dating, the Beaufort Group rocks are considered to range between Middle Permian ( Wordian) to Early Triassic (Anisian) in age. Background During the period when sedimentation of the Beaufort Group rocks took place, the Ecca sea had retreated to the northeastern Karoo Basin. All sediment deposition at this time took place in a terrestrial, although in a predominantly fluvial or alluvial environment that was seasonally arid. This environment covered a vast area and deposition was influenced by a retroarc foreland basin. This foreland system was caused by crustal uplif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
