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Galesaurus Block
''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] |
Induan
The Induan is the first age of the Early Triassic epoch in the geologic timescale, or the lowest stage of the Lower Triassic series in chronostratigraphy. It spans the time between 251.902 Ma and Ma (million years ago). The Induan is sometimes divided into the Griesbachian and the Dienerian subages or substages. The Induan is preceded by the Changhsingian (latest Permian) and is followed by the Olenekian. The Induan is roughly coeval with the regional Feixianguanian Stage of China. Geology Stratigraphy The Triassic is the first period of the Mesozoic era. It is subdivided into the Lower, Middle, and Upper Triassic series, which are further subdivided into stages. The Induan is the first stage of the Lower Triassic, from 251.9 million to 251.2 million years ago, spanning the first 700,000 years after the Permian–Triassic extinction event. Stages can be defined globally or regionally. For global stratigraphic correlation, the International Commission on Stratigraphy (ICS) r ... [...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] |
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] |
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] |
Procynosuchus
''Procynosuchus'' (Greek: "Before dog crocodile") is an extinct genus of cynodonts from the Late Permian. It is considered to be one of the earliest and most basal cynodonts. It was 60 cm (2 ft) long. Remains of ''Procynosuchus'' have been found in Russia, Germany, Zambia and South Africa.T. S. Kemp: ''The Origin and Evolution of Mammals'' Oxford University Press, 2005. Paleobiology As one of the earliest cynodonts, ''Procynosuchus'' has many primitive features, but it also has features that distinguish it from all other early therapsids. Some of these features were interpreted by Kemp (1980) as adaptations for a semi-aquatic lifestyle. For example, the wide zygapophyses of the vertebrae allow for a high degree of lateral flexibility, and ''Procynosuchus'' may have used anguilliform locomotion, or eel-like undulation, to swim through the water. The tail of ''Procynosuchus'' is also unusually long for a cynodont. The long haemal arches would have given the tail a lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dvinia
''Dvinia'' is an extinct genus of cynodonts found in the Salarevo Formation of Sokolki on the Northern Dvina River near Kotlas in Arkhangelsk Oblast, Russia. It is the only known member of the family Dviniidae. Its fossil remains date from the Late Permian and were found with ''Inostrancevia'', ''Scutosaurus'' and '' Vivaxosaurus''. ''Dvinia'' was a small omnivore possessing a large temporal opening typical of advanced therapsids, with a thin postorbital bar separating the eye from the muscle attachment. As a cynodont, it was closely related to mammals. The dentition consisted of a set of small incisors followed by 2 canines and 10-14 postcanines. 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 Further reading * Patricia ... [...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] |
Lycosuchus
''Lycosuchus'' ("wolf crocodile") is an extinct genus of carnivorous therocephalians which lived in the Middle Permian 265—260 Ma existing for approximately . As a member of the Lycosuchidae, the genus represents one of the earliest diverging therocephalians. The type species ''Lycosuchus vanderrieti'' is known from a handful of well-preserved specimens featuring the cranium and lower jaw; the holotype US D173 housed at the University of Stellenbosch, South Africa, is a near complete occluded skull. Specimen MB.R. 995, housed at the Museum für Naturkunde Berlin, Germany, consists of a near complete and isolated lower jaw, along with a partial snout and brain case. With the help of μCT data, Pusch et al (2020) described the endocranial anatomy of ''Lycosuchus vanderrieti''. It was a medium-sized predator, reaching 1.2 m (3.8 ft) in length with a skull 23 cm long., typical of early therocephalians. ''L. vanderrieti'' bore two functional canines in each maxilla, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutheriodontia
Eutheriodontia is a clade of therapsids which appear during the Middle Permian and which includes therocephalians and cynodonts, this latter group including mammals and related forms. With the dicynodonts, they form one of two lineages of therapsids that survived the Permian extinction and which diversified again during the Triassic, before the majority of them disappeared before or during the Triassic–Jurassic extinction, except for a lineage of cynodonts that would later give rise to mammals. Classification The clade was named in 1986 by James Allen Hopson and Herbert Richard Barghusen, the name meaning the "true Theriodontia". Within Hopson's system, the Eutheriodontia are the sister group of the Gorgonopsia within the Theriodontia. A close relationship between therocephalians and cynodonts had been recognized for many years. In 2001 the Eutheriodontia were defined as the least inclusive clade including Mammalia and ''Bauria''.James A. Hopson and James W. Kitching, 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gorgonopsidae
Gorgonopsia (from the Greek Gorgon, a mythological beast, and 'aspect') is an extinct clade of sabre-toothed therapsids from the Middle to Upper Permian roughly 265 to 252 million years ago. They are characterised by a long and narrow skull, as well as elongated upper and sometimes lower canine teeth and incisors which were likely used as slashing and stabbing weapons. Postcanine teeth are generally reduced or absent. For hunting large prey, they possibly used a bite-and-retreat tactic, ambushing and taking a debilitating bite out of the target, and following it at a safe distance before its injuries exhausted it, whereupon the gorgonopsian would grapple the animal and deliver a killing bite. They would have had an exorbitant gape, possibly in excess of 90°, without having to unhinge the jaw. They markedly increased in size as time went on, growing from small skull lengths of in the Middle Permian to bear-like proportions of up to in the Upper Permian. The latest gorgonop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theriodontia
The theriodonts (clade Theriodontia) are a major group of therapsids which appeared during the Middle Permian and which includes the gorgonopsians and the eutheriodonts, itself including the therocephalians and the cynodonts. Naming In 1876, Richard Owen named a suborder Theriodontia, which he divided into the Cynodontia and the Gomphodontia. The modern clade concept was devised by James Allen Hopson. In his system, Theriodontia fall into two main groups: the Gorgonopsia and the Eutheriodontia. The latter consist of the Therocephalia and Cynodontia.J.A. Hopson. 1999. "Therapsids". ''Encyclopedia of Paleontology'' 2: 1256-1266 Evolution Theriodonts appeared at the same time as their sister group within the Neotherapsida, the Anomodontia, about 270 million years ago, in the Middle Permian. Even these early theriodonts were more mammal-like than their anomodont and dinocephalian contemporaries. Early theriodonts may have been warm-blooded. Early forms were carnivorous, but sev ... [...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] |
