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Scylacosaur
Scylacosauria is a clade of therocephalian therapsids. It includes the basal family Scylacosauridae and the infraorder Eutherocephalia. Scylacosauridae and Eutherocephalia form this clade to the exclusion of Lycosuchidae, the most basal therocephalian family. Thus, Scylacosauria includes all therocephalians except lycosuchids. Below is a cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ... showing the phylogenetic position of Scylacosauria: References Therocephalia Guadalupian first appearances Middle Triassic extinctions Tetrapod unranked clades {{paleo-Therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lycosuchidae
Lycosuchidae is a Family (biology), family of therocephalians (an extinct type of therapsids, broader group which modern mammals belong to) known from fossils from what is now the Beaufort Group of South Africa and that lived during the Middle Permian, Middle to Late Permian between roughly 265 to 258 million years ago. It currently includes only two genera each with a single species, ''Lycosuchus'', represented by ''L. vanderrieti'', and ''Simorhinella'', represented by ''S. baini'', both named by paleontologist Robert Broom in 1903 and 1915, respectively (though ''Simorhinella'' was not recognised as a lycosuchid until 2014). Both species are large predators characterised by their size, reduced tooth counts with large, almost "Saber-toothed predator, sabre toothed" canine teeth, and relatively short, broad and low snouts. Lycosuchids were once thought to be defined by having two simultaneously functional pairs of canines, so-called "double canines", instead of a single pair of l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Therocephalia
Therocephalia is an extinct clade of therapsids (mammals and their close extinct relatives) from the Permian and Triassic periods. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their teeth, suggest that they were carnivores. Like other non-mammalian synapsids, therocephalians were once described as "mammal-like reptiles". Therocephalia is the group most closely related to the cynodonts, which gave rise to the mammals. Indeed, it had been proposed that therocephalians themselves may have given rise to the cynodonts, and therefore that therocephalians as recognised are paraphyletic in relation to cynodonts and so not a clade. Conventionally, however, Therocephalia is regarded as the sister clade of Cynodontia, together forming the clade Eutheriodontia. The close relationship of Therocephalia to Cynodontia takes evidence in a variety of skeletal features. Most notable is that the skull roof is narrowed between two enlarged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Eutherocephalia
Eutherocephalia ("true beast head") is an extinct clade of advanced therocephalian therapsids. Eutherocephalians are distinguished from the lycosuchids and scylacosaurids, two early therocephalian families. While lycosuchids and scyalosaurids became extinct by the end of the Permian period, eutherocephalians survived the Permian–Triassic extinction event. The group eventually became extinct in the Middle Triassic. Characteristics The Eutherocephalians evolved several mammal-like traits through convergent evolution with Cynodontia. Among those traits were the loss of palatine teeth and the reduction of the parietal eye. The latter organ is instrumental in thermoregulation among lizards and snakes, indicating both eutherocephalians and cynodonts were evolving toward a more active, homeothermic lifestyle, though the eye never fully disappeared in the eutherocephalians. Classification The clade Eutherocephalia contains the majority of therocephalians, yet the phylogenetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Middle Permian
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 is also 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 the Lopingian. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is divided in chronostratigraphy. The Middle Triassic spans the time between annum, Ma and Ma (million years ago). It is preceded by the Early Triassic Epoch and followed by the Late Triassic Epoch. The Middle Triassic is divided into the Anisian and Ladinian age (geology), ages or stage (stratigraphy), stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of stratum, rock strata with approximately Middle Triassic age, found in western Europe. Middle Triassic life Following the Permian–Triassic extinction event, the most devastating of all mass-extinctions, life recovered slowly. In the Middle Triassic, many groups of organisms reached higher diversity again, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Porosteognathus
''Porosteognathus'' is an extinct genus of therocephalian therapsids. Remains have been found at Isheevo in Russia (Republic of Tatarstan Tatarstan, officially the Republic of Tatarstan, sometimes also called Tataria, is a Republics of Russia, republic of Russia located in Eastern Europe. It is a part of the Volga Federal District; and its capital city, capital and largest city i ...).Michael J. Benton, Mikhail A. Shishkin, David M. Unwin, and Evgenii N. Kurochkin (2003): ''The Age of Dinosaurs in Russia and Mongolia'', Cambridge University Press It is known from the Middle Permian. References Extinct animals of Russia Scylacosauridae Therocephalia genera Fossil taxa described in 1955 {{paleo-therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
1994 In Paleontology
References * Calvo, J.O. (1994). Gastroliths in sauropod dinosaurs. Gaia, 10: 205–208. * Martin, James E.; 1994; Gastric residues in marine reptiles from the Late Cretaceous Pierre Shale in South Dakota; their bearing on extinction; Journal of Vertebrate Paleontology; 14(3, Suppl.) pp. 36; University of Oklahoma * Pasch, A. D., K. C. May. 2001. Taphonomy and paleoenvironment of hadrosaur (Dinosauria) from the Matanuska Formation (Turonian) in South-Central Alaska. In: ''Mesozoic Vertebrate Life''. Ed.s Tanke, D. H., Carpenter, K., Skrepnick, M. W. Indiana University Press. Pages 219–236. * Sanders F, Manley K, Carpenter K. Gastroliths from the Lower Cretaceous sauropod Cedarosaurus weiskopfae. In: Tanke D.H, Carpenter K, editors. Mesozoic vertebrate life: new research inspired by the paleontology of Philip J. Currie. Indiana University Press; Bloomington, IN: 2001. pp. 166–180. 1994 in paleontology, 1990s in paleontology 1994 in science, Paleontology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Scylacosauridae
Scylacosauridae is an extinct family of therocephalian therapsids. Scylacosaurids lived during the Permian period and were among the most basal therocephalians. The family was named by South African paleontologist Robert Broom in 1903. Scylacosaurids have long snouts and unusual saber-like canine teeth. References External links Scylacosauridaein the Paleobiology Database The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database originated in the NCEAS-funded Phanerozoic Marine Pale ... Prehistoric therapsid families Guadalupian first appearances Lopingian extinctions {{Paleo-therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy adopted by most biological fields. The common ancestor may be an individual, a population, or a species (extinct or Extant taxon, extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed ''monophyletic'' (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming Taxon, taxa that are not clades; that is, taxa that are not Monophyly, monophyletic. Some of the relationships between organisms that the molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Basal (phylogenetics)
In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, Phylogenetic diversity, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a 'key innovation' implies some degree of correlation between evolutionary innovation and cladogenesis, diversification. However, such a correlation does not make a given ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
