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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 rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutherocephalians
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 rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therocephalia
Therocephalia is an extinct suborder of eutheriodont therapsids (mammals and their close relatives) from the Permian and Triassic. 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. This relationship takes evidence in a variety of skeletal features. The fossils of therocephalians are numerous in the Karoo of South Africa, but have also been found in Russia, China, Tanzania, Zambia, and Antarctica. Early therocephalian fossils discovered in Middle Permian deposits of South Africa support a Gondwanan origin for the group, which seems to have spread quickly across Earth. Although almost every therocephalian lineage ended during the great Permian–Triassic extinction event, a few represe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichibengops
''Ichibengops'' is an extinct genus of therocephalian therapsids known from the type species ''Ichibengops munyamadziensis'', which lived in what is now Zambia during the Late Permian. ''Ichibengops'' was named in 2015 on the basis of fossils found in the Wuchiapingian-age Madumabisa Mudstone Formation in the Luangwa Basin. Therocephalians have been known from the Luangwa Basin for decades, yet ''Ichibengops'' was the first endemic Zambian therocephalian to have been described in detail. Phylogenetic analysis indicates that it is a basal member of the clade Eutherocephalia, lying just outside a clade containing hofmeyriids, whaitsiids, and baurioids. ''Ichibengops'' is the sister taxon of the Russian therocephalian ''Chthonosaurus''; together they form one of several known African-Russian sister taxon pairs of eutherocephalians, which indicate that eutherocephalians could freely disperse across most of Pangea during the Late Permian. Like the fellow therocephalian ''Euchambersia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scylacosuchus
''Scylacosuchus'' is an extinct genus of therocephalian therapsids. It was a predatory eutherocephalian that lived in Lopingian epoch. Its fossils were found in Orenburg Oblast of Russia. The type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ... is ''Scylacosuchus orenburgensis''. References * Valentin P. Tverdokhlebov, Galina I. Tverdokhlebova, Alla V. Minikh, Mikhail V. Surkov, and Michael J. Benton, (2005) Upper Permian vertebrates and their sedimentological context in the South Urals, Russia, ''Earth-Science Reviews'' 69 27-77 55 Eutherocephalians Therocephalia genera Lopingian synapsids of Europe Prehistoric synapsids of Europe Fossil taxa described in 1968 Taxa named by Leonid Petrovich Tatarinov {{paleo-therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanictidopidae
Nanictidopidae is an extinct family of therocephalian therapsids from the Late Permian. Two genera are currently included in the family, '' Nanictidops'' from South Africa and '' Purlovia'' from Russia. Nanictidopids have short skulls and were probably herbivorous. Description In comparison to other therocephalians, nanictidopids are relatively large, with skulls ranging from in length. Nanictidopids are characterized by their shortened skulls that appear triangular when viewed from above. The temporal region of the skull is very wide. Their skulls are similar to those of hofmeyriids, and the superfamily Nanictidopoidea has been established to unite these two groups. Nanictidopids have enlarged canine teeth in their upper and lower jaws, while the teeth behind them are very small. Small bumps and ridges cover parts of the upper and lower jaws. The parietal region at the back of the skull forms a sagittal crest. The postorbital bones that make up the back of the eye sockets are v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caodeyao
''Caodeyao'' (in reference to the village of Caodeyao) is a genus of therocephalian that lived in what is now China during the late Permian. It was found in the Naobaogou Formation The Naobaogou Formation is a geological formation in the Daqing Mountains of China. It is likely of Lopingian age. It consists of three rhythms of sediment, labelled members I-III primarily of purple siltstone Siltstone, also known as aleurol .... It contains one species, ''Caodeyao liuyufengi'', named in 2020 by Jun Liu and Fernando Abdala. References Eutherocephalians Therocephalia genera Lopingian synapsids of Asia Fossil taxa described in 2020 {{Paleo-therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chthonosaurus
''Chthonosaurus'' is an extinct genus of eutherocephalian therapsids from the Late Permian Kutulukskaya Formation of Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the .... The type species ''Chthonosaurus velocidens'' was named in 1955. References Eutherocephalians Therocephalia genera Lopingian synapsids of Europe Fossils of Russia Fossil taxa described in 1955 {{paleo-therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akidnognathidae
Akidnognathidae is an extinct family of therocephalian therapsids from the Late Permian and Early Triassic of South Africa, Russia and China. The family includes many large-bodied therocephalians that were probably carnivorous, including ''Moschorhinus'' and ''Olivierosuchus''. One akidnognathid, ''Euchambersia'', may even have been venomous. Akidnognathids have robust skulls with a pair of large caniniform teeth in their upper jaws. The family is morphologically intermediate between the more basal therocephalian group Scylacosauridae and the more derived group Baurioidea. Classification History The first family-level name used to classify an akidnognathid was Euchambersidae, erected by South African paleontologist Lieuwe Dirk Boonstra in 1934,Boonstra L.D. 1934. "A contribution to the morphology of the mammal-like reptiles of the suborder Therocephalia". ''Annals of the South African Museum'', 31: 215–267 in reference for the genus ''Euchambersia'', which is possibly one of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hofmeyriidae
Hofmeyriidae is a family of therocephalian therapsids. It includes the genus ''Ictidostoma''. References External links Hofmeyriidaein the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ... Eutherocephalians Permian first appearances Permian extinctions Prehistoric therapsid families {{paleo-Therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas '' homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to parallel evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parietal Eye
A parietal eye, also known as a third eye or pineal eye, is a part of the epithalamus present in some vertebrates. The eye is located at the top of the head, is photoreceptive and is associated with the pineal gland, regulating circadian rhythmicity and hormone production for thermoregulation. The hole in the head which contains the eye is known as a pineal foramen or parietal foramen, since it is often enclosed by the parietal bones. Presence in various animals The parietal eye is found in the tuatara, most lizards, frogs, salamanders, certain bony fish, sharks, and lampreys. It is absent in mammals, but was present in their closest extinct relatives, the therapsids, suggesting it was lost during the course of the mammalian evolution due to it being useless in endothermic animals. It is also absent in the ancestrally endothermic ("warm-blooded") archosaurs such as birds. The parietal eye is also lost in ectothermic ("cold-blooded") archosaurs like crocodilians, and in turtles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
