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Theriognathus Microps
''Theriognathus'' (from Greek therion: beast, mammal, Greek, gnathos, “jaw,” +us, pronounced THEH-ree-OG-nah-thuss) is an extinct genus of therocephalian therapsid belonging to the family Whaitsiidae, known from fossils from South Africa, Zambia, and Tanzania. ''Theriognathus'' has been dated as existing during the Late Permian. Although ''Theriognathus'' means mammal jaw, the lower jaw is actually made up of several bones as seen in modern reptiles, in contrast to mammals. ''Theriognathus'' displayed many different reptilian and mammalian characteristics. For example, ''Theriognathus'' had canine teeth like mammals, and a secondary palate, multiple bones in the mandible, and a typical reptilian jaw joint, all characteristics of reptiles. It is speculated that ''Theriognathus'' was either carnivorous or omnivorous based on its teeth, and was suited to hunting small prey in undergrowth. This synapsid adopted a sleek profile of a mammalian predator, with a narrow snout and aro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wuchiapingian
In the geologic timescale, the Wuchiapingian or Wujiapingian (from in the Liangshan area of Hanzhong, Shaanxi Province) is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or Series. The Wuchiapingian spans the time between and million years ago (Ma). It was preceded by the Capitanian and followed by the Changhsingian. Regional stages with which the Wuchiapingian is coeval or overlaps include the Djulfian or Dzhulfian, Longtanian, Rustlerian, Saladoan, and Castilian. Stratigraphic definitions The Wuchiapingian was first used in 1962, when the Lopingian Series of southwestern China was divided in the Changhsingian and Wuchiapingian Formations. In 1973 the Wuchiapingian was first used as a chronostratigraphic unit (i.e. a stage, as opposed to a formation, which is a lithostratigraphic unit). The base of the Wuchiapingian Stage is defined as the place in the stratigraphic record where the conodont species ''Clarkin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guadalupian
The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0.5 – 259.1 ± 0.4 Mya. The series saw the rise of the therapsids, a minor extinction event called Olson's Extinction and a significant mass extinction called the end-Capitanian extinction event. The Guadalupian was previously known as the Middle Permian. Name and background The Guadalupian is the second and middle series or epoch of the Permian. Previously called Middle Permian, the name of this epoch is part of a revision of Permian stratigraphy for standard global correlation. The name "Guadalupian" was first proposed in the early 1900s, and approved by the International Subcommission on Permian Stratigraphy in 1996. References to the Middle Permian still exist. The Guadalupian was preceded by the Cisuralian and followed by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theriognathus
''Theriognathus'' (from Greek therion: beast, mammal, Greek, gnathos, “jaw,” +us, pronounced THEH-ree-OG-nah-thuss) is an extinct genus of therocephalian therapsid belonging to the family Whaitsiidae, known from fossils from South Africa, Zambia, and Tanzania. ''Theriognathus'' has been dated as existing during the Late Permian. Although ''Theriognathus'' means mammal jaw, the lower jaw is actually made up of several bones as seen in modern reptiles, in contrast to mammals. ''Theriognathus'' displayed many different reptilian and mammalian characteristics. For example, ''Theriognathus'' had canine teeth like mammals, and a secondary palate, multiple bones in the mandible, and a typical reptilian jaw joint, all characteristics of reptiles. It is speculated that ''Theriognathus'' was either carnivorous or omnivorous based on its teeth, and was suited to hunting small prey in undergrowth. This synapsid adopted a sleek profile of a mammalian predator, with a narrow snout and aro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notosollasia
''Theriognathus'' (from Greek therion: beast, mammal, Greek, gnathos, “jaw,” +us, pronounced THEH-ree-OG-nah-thuss) is an extinct genus of therocephalian therapsid belonging to the family Whaitsiidae, known from fossils from South Africa, Zambia, and Tanzania. ''Theriognathus'' has been dated as existing during the Late Permian. Although ''Theriognathus'' means mammal jaw, the lower jaw is actually made up of several bones as seen in modern reptiles, in contrast to mammals. ''Theriognathus'' displayed many different reptilian and mammalian characteristics. For example, ''Theriognathus'' had canine teeth like mammals, and a secondary palate, multiple bones in the mandible, and a typical reptilian jaw joint, all characteristics of reptiles. It is speculated that ''Theriognathus'' was either carnivorous or omnivorous based on its teeth, and was suited to hunting small prey in undergrowth. This synapsid adopted a sleek profile of a mammalian predator, with a narrow snout and aro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladistics
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived characteristics ( synapomorphies'')'' that are not present in more distant groups and ancestors. However, from an empirical perspective, common ancestors are inferences based on a cladistic hypothesis of relationships of taxa whose character states can be observed. Theoretically, a last common ancestor and all its descendants constitute a (minimal) clade. Importantly, all descendants stay in their overarching ancestral clade. For example, if the terms ''worms'' or ''fishes'' were used within a ''strict'' cladistic framework, these terms would include humans. Many of these terms are normally used paraphyletically, outside of cladistics, e.g. as a ' grade', which are fruitless to precisely delineate, especially when including extinct species. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic group (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term was coined by Willi Hennig to apply to well-known taxa like Reptilia ( reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor, including all extant reptiles as well as the extinct synaps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charassognathus
''Charassognathus'' (meaning 'notched jaw') is an extinct genus of Late Permian cynodonts. Described in 2007 from a locality near Fraserburg, South Africa, ''Charassognathus'' is one of the earliest and most basal cynodonts. It is known only from the holotype, which dates from the Late Permian Period. The type and only species is ''C. gracilis''. The holotype ( SAM-PK-K 10369), found in the ''Tropidostoma'' Assemblage Zone of the Teekloof Formation, is made up of a crushed skull, partial lower jaw and one leg. ''Charassognathus'' was a quadrupedal predator. It was named for a notch on its coronoid process which most likely was the insertion point for a chewing muscle, the adductor mandibulae externus. ''Charassognathus'' was a small animal, with a skull only in length. Since the body of ''Charassognathus'' has not been discovered, its full length remains unknown, but estimates have been made at . Description ''Charassognathus'' has a snout that makes up slightly less t ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicynodont
Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivorous animals with a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typically toothless beak, unique amongst all synapsids. Dicynodonts first appeared in Southern Pangaea during the mid-Permian, ca. 270–260 million years ago, and became globally distributed and the dominant herbivorous animals in the Late Permian, ca. 260–252 Mya. They were devastated by the end-Permian Extinction that wiped out most other therapsids ca. 252 Mya. They rebounded during the Triassic but died out towards the end of that period. They were the most successful and diverse of the non-mammalian therapsids, with over 70 genera known, varying from rat-sized burrowers to elephant-sized browsers. Characteristics The dicynodont skull is highly specialised, light but strong, with the synapsid temporal openings at the rear of the sk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sir Richard Owen
Sir Richard Owen (20 July 1804 – 18 December 1892) was an English biologist, comparative anatomist and paleontologist. Owen is generally considered to have been an outstanding naturalist with a remarkable gift for interpreting fossils. Owen produced a vast array of scientific work, but is probably best remembered today for coining the word '' Dinosauria'' (meaning "Terrible Reptile" or "Fearfully Great Reptile"). An outspoken critic of Charles Darwin's theory of evolution by natural selection, Owen agreed with Darwin that evolution occurred, but thought it was more complex than outlined in Darwin's ''On the Origin of Species''. Owen's approach to evolution can be considered to have anticipated the issues that have gained greater attention with the recent emergence of evolutionary developmental biology. Owen was the first president of the Microscopical Society of London in 1839 and edited many issues of its journal – then known as ''The Microscopic Journal''. Owen also c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kotelnich
Kotelnich (russian: Коте́льнич; chm, Кäкшäр) is a river port town in Kirov Oblast, Russia, located on the right bank of the Vyatka River near its confluence with the Moloma, along the route of the Trans-Siberian Railway, southwest of Kirov. Population: History The locality of Koksharov () was first mentioned in 1143 as a Mari town. In 1182, it was occupied by Russians and renamed Kotelnich, from the word ''kotel'' (now ''kotlovina''), meaning "hollow", "depression".Е. М. Поспелов. "Географические названия мира". Москва, 1998, p. 218. Town status was granted to it in 1780. It became one of the main settlements of the Vyatka Land. The city of Kotelnich is well known all over Russia and in some foreign countries due to location of ancient fossil vertebrates – Pareiasaurus. Pareiasaurus – is a large reptile with spurs in the buccal region of the skull. These animals grew to about 3 meters long and inhabited E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
