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Tikitherium
''Tikitherium'' is an extinct genus of mammaliaforms from India, known from a single upper tooth. Originally argued to be a primitive mammaliaform from the Late Triassic, a 2024 study argued that it actually represented the remains of a shrew from the Neogene. ''Tikitherium'' refers to Tiki, the village located near the Tiki Formation where the specimen was originally thought to have come from, and ''therium'' is Greek for “Beast”. The species was named ''copei'' in honor of Edward Drinker Cope for his pioneering discoveries towards understanding mammalian molars.Datta, P.M. 2005Earliest Mammal with Transversely Expanded Upper Molar from the Late Triassic (Carnian) Tiki Formation, South Rewa Gondwana Basin, India ''Journal of Vertebrate Paleontology''. 25(1):200-207. History and discovery ''Tikitherium copei'' was first described by Datta in 2005. The first and only specimen is an upper tooth that was thought to have discovered in the lower part of the Late Triassic Tiki F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Docodonta
Docodonta is an Order (biology), order of extinct Mesozoic Mammaliaformes, mammaliaforms (advanced cynodonts closely related to true Crown group, crown-group mammals). They were among the most common mammaliaforms of their time, persisting from the Early Jurassic to the Early Cretaceous across the continent of Laurasia (modern-day North America, Europe, and Asia). They are distinguished from other early mammaliaforms by their relatively complex Molar (tooth), molar teeth. Docodontan teeth have been described as "pseudotribosphenic": a cusp on the inner half of the upper molar grinds into a basin on the front half of the lower molar, like a Mortar and pestle, mortar-and-pestle. This is a case of convergent evolution with the Tribosphenic molar, tribosphenic teeth of therian mammals. There is much uncertainty for how docodontan teeth developed from their simpler ancestors. Their closest relatives may have been certain Triassic "Symmetrodonta, symmetrodonts", namely ''Woutersia'', an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammaliaform
Mammaliaformes ("mammalian forms") is a clade of synapsid tetrapods that includes the crown group mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts during the Late Triassic. It is defined as the clade originating from the most recent common ancestor of Morganucodonta and the crown group mammals; the latter is the clade originating with the most recent common ancestor of extant Monotremata, Marsupialia and Placentalia. Besides Morganucodonta and the crown group mammals, Mammaliaformes also includes Docodonta and ''Hadrocodium''. Mammaliaformes is a term of phylogenetic nomenclature. In contrast, the assignment of organisms to class (biology), class Mammalia has traditionally been founded on phenotypic trait, traits and, on this basis, Mammalia is slightly more inclusive than Mammaliaformes. In particular, trait-based taxonomy generally includes ''Adelobasileus'' and ''Sinoconodon'' in Mammalia, though they fall outside the Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiki Formation
The Tiki Formation is a Late Triassic (Carnian to Norian) geologic Formation (geology), formation in Madhya Pradesh, northern India. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus. Phytosaur remains attributable to the genus ''Volcanosuchus'' have also been found in the Tiki Formation.Chatterjee, 1978 The genera ''Tikiodon'', ''Tikitherium'' and ''Tikisuchus'' and species ''Rewaconodon, Rewaconodon tikiensis'', ''Hyperodapedon, Hyperodapedon tikiensis'' and ''Parvodus, Parvodus tikiensis'' have been named after the Tiki Formation. Paleobiota Cynodonts Reptiles Teeth similar to ''Galtonia'', ''Protecovasaurus'', and ''Azendohsaurus'' are known from the formation. Claws similar to Shuvosauridae, shuvosaurids and Dinosaur, dinosaurs have also been reported, though their exact identification is questionable. Saurischia, Saurischian dinosaurs may have been present based on vertebrae a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cusp (anatomy)
A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has two cusps, is also known as the bicuspid valve, and the tricuspid valve has three cusps. In humans A cusp is an occlusal or incisal eminence on a tooth. Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps. In certain populations the maxillary molars, especially first molars, will possess a fifth cusp situated on the mesiolingual cusp known as the Cusp of Carabelli. One other variation of the upper first premolar is the 'Uto-Aztecan' upper premolar. It is a bulge on the buccal cusp that is only found in Native American Indians, with highest frequencies of occurrence in Arizona. The name is not a d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suncus
''Suncus'' is a genus of shrews in the family Soricidae. Classification *Genus ''Suncus'' ** Taita shrew, ''Suncus aequatorius'' ** Black shrew, ''Suncus ater'' ** Day's shrew, ''Suncus dayi'' ** Etruscan shrew, ''Suncus etruscus'' ** Sri Lankan shrew, ''Suncus fellowesgordoni'' ** Bornean pygmy shrew, ''Suncus hosei'' ** Hutu-Tutsi dwarf shrew The Hutu-Tutsi dwarf shrew (''Suncus hututsi'') is a species of mammal in the family Soricidae. It is known from a small portion of the mountains of tropical Africa. Taxonomy It is named after the Hutus and Tutsis, the two major ethnic groups ..., ''Suncus hututsi'' ** Least dwarf shrew, ''Suncus infinitesimus'' ** Greater dwarf shrew, ''Suncus lixa'' ** Madagascan pygmy shrew, ''Suncus madagascariensis'' ** Malayan pygmy shrew, ''Suncus malayanus'' ** Climbing shrew, ''Suncus megalurus'' ** Flores shrew, ''Suncus mertensi'' ** Asian highland shrew, ''Suncus montanus'' ** Asian house shrew, ''Suncus murinus'' ** Remy' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypocone
A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has two cusps, is also known as the bicuspid valve, and the tricuspid valve has three cusps. In humans A cusp is an occlusal or incisal eminence on a tooth. Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps. In certain populations the maxillary molars, especially first molars, will possess a fifth cusp situated on the mesiolingual cusp known as the Cusp of Carabelli. One other variation of the upper first premolar is the 'Uto-Aztecan' upper premolar. It is a bulge on the buccal cusp that is only found in Native American Indians, with highest frequencies of occurrence in Arizona. The name is not a d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocone
A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has two cusps, is also known as the bicuspid valve, and the tricuspid valve has three cusps. In humans A cusp is an occlusal or incisal eminence on a tooth. Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps. In certain populations the maxillary molars, especially first molars, will possess a fifth cusp situated on the mesiolingual cusp known as the Cusp of Carabelli. One other variation of the upper first premolar is the 'Uto-Aztecan' upper premolar. It is a bulge on the buccal cusp that is only found in Native American Indians, with highest frequencies of occurrence in Arizona. The name is not a dental ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Itatodon
''Itatodon'' is an extinct genus of primitive mammaliaforms known from the Bathonian aged Itat Formation of Russia. The genus is named after the formation, with the species being named after Leonid Petrovich Tatarinov who described the first docodont from Asia. It is known from a holotype right lower molar and referred isolated right lower molar and fragment of the left lower molar. When it was first described, it was thought to be a docodontan, but one recent phylogenetic studies have assigned it, along with its close relative '' Paritatodon'' to Shuotheriidae Shuotheriidae is a small family of Jurassic mammaliaforms whose remains are found in China, Great Britain and possibly Russia. They have been proposed to be close relatives of Australosphenida (which often controversially includes monotremes), t ..., while others continue to consider it a docodont. References Shuotheriidae Bathonian life Middle Jurassic synapsids of Asia Jurassic Russia Fossils of Russia F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Docodon
''Docodon'' (meaning 'beam tooth') is an extinct docodont mammaliaform from the Late Jurassic of western North America. It was the first docodont to be named. Description ''Docodon'' was the first docodontan cynodont found and named, and later gave its name to the family Docodontidae as well as the order Docodonta.Kretzoi, M. (1946). "On Docodonta, a new order of Jurassic Mammals". ''Anneles Historico-Naturales Musei Nationalis Hungarici''. 39 :108-111. Docodonts had more complex shaped teeth than other early non-mammalian mammaliaforms, with piercing and crushing surfaces that would have allowed members of this family to eat a wider range of food types. These complex teeth are more similar to those of later mammal groups, but evolved independently of them. Unlike many of its coexisting mammal relatives from the Mesozoic, ''Docodon'' is known from a large number of teeth and jaws of differing growth stages. This has made it possible to study the growth of this docodontan, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haldanodon
''Haldanodon'' is an extinct docodont mammaliaform which lived in the Upper Jurassic (Kimmeridgian, about 145 million years ago). Its fossil remains have been found in Portugal, in the well-known fossil locality of Guimarota, which is in the Alcobaça Formation. It may have been a semi-aquatic burrowing insectivore, similar in habits to desmans and the platypus. Several specimens are known, include a partial skeleton and well-preserved skulls. Description ''Haldanodon'' was about as long as a desman, and may have had a similar ecology. The skull was low and triangular when seen from above. For many years it had the best-known skull material of any docodont, making it vital for understanding the taxonomic position of that mammaliaform group. It was the first Mesozoic mammaliaform discovered to possess Nasal concha, turbinal plates, a complex feature of mammalian Nasal cavity, nasal cavities. However, it also retained some curiously primitive traits in common with non-mammaliaform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
