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Sphenacodontoidea
Sphenacodontoidea is a node-based clade that is defined to include the most recent common ancestor of Sphenacodontidae and Therapsida and its descendants (including mammals). Sphenacodontoids are characterised by a number of synapomorphies concerning proportions of the bones of the skull and the teeth. The sphenacodontoids evolved from earlier sphenacodonts such as '' Haptodus'' and '' Ianthodon'' via a number of transitional stages of small, 1-10 kg, faunivore animals. The possible common ancestor of sphenacodontids and therapsids was a carnivorous synapsid that reached moderate or large size and more closely resembled the land-dominant Early Permian sphenacodontids than the small ''Haptodus''. The first predators among Sphenacodontoidea, like '' Shashajaia'', appeared in the tropical western part of Pangea in the Late Carboniferous. Later, in Permian, sphenacodontoids gave rise to the dominant terrestrial carnivores in both sphenacodontid and therapsid groups. Classificat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodont
Sphenacodontia is a stem-based clade of derived synapsids. It was defined by Amson and Laurin (2011) as "the largest clade that includes '' Haptodus baylei'', '' Haptodus garnettensis'' and '' Sphenacodon ferox'', but not '' Edaphosaurus pogonias''". They first appear during the Late Pennsylvanian (Upper Carboniferous) epoch. From the end of the Carboniferous to the end of the Permian, most of them remained large, with only some secondarily becoming small in size. Basal Sphenacodontia constitute a transitional evolutionary series from early pelycosaurs to ancestral therapsids (which in turn were the ancestors of more advanced forms and finally the mammals). One might say that the sphenacodontians are proto-therapsids (even though there is almost a 30-million-years gap between the separation of the ancestors of therapsids from other sphenacodontians and the first appearance of therapsids in the fossil record). Characteristics The defining characteristics include a thickenin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodontia
Sphenacodontia is a stem-based taxon, stem-based clade of derived synapsids. It was defined by Amson and Laurin (2011) as "the largest clade that includes ''Haptodus baylei'', ''Haptodus garnettensis'' and ''Sphenacodon ferox'', but not ''Edaphosaurus pogonias''". They first appear during the Late Pennsylvanian (Upper Carboniferous) epoch. From the end of the Carboniferous to the end of the Permian, most of them remained large, with only some secondarily becoming small in size. Basal (phylogenetics), Basal Sphenacodontia constitute a Transitional fossils, transitional evolutionary series from early pelycosaurs to ancestral therapsids (which in turn were the ancestors of cynodont, more advanced forms and finally the mammals). One might say that the sphenacodontians are proto-therapsids (even though there is almost a 30-million-years gap between the separation of the ancestors of therapsids from other sphenacodontians and the first appearance of therapsids in the fossil record). Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutleria Wilmarthi
''Cutleria'' is an extinct genus of basal sphenacodontids or derived stem- sphenacodontoid known from the Early Permian period ( Sakmarian stage) of Colorado, United States. It contains a single species, ''Cutleria wilmarthi''. Discovery ''Cutleria'' is known only from the holotype specimen USNM 22099, a fractured but three-dimensionally preserved, a nearly complete skull and articulated partial postcranial skeleton (including vertebral column, ribs and several girdle and limb elements). It was collected at locality 3, near Placerville of San Miguel County, Colorado, from the Cutler Formation, dating to the Sakmarian stage of the Cisuralian series. MCZ 2987, a tip of the rostrum and some teeth collected 2.5 km from the type locality (from localities 11–13), was originally referred to ''C. wilmarthi'' by Lewis and Vaughn (1965). A redescription of sphenacodonts by Michel Laurin (1993 and 1994), revealed that it cannot be assigned to any named sphenacodo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodontidae
Sphenacodontidae (Greek: "wedge point tooth family") is an extinct family (biology), family of sphenacodontoidea, sphenacodontoid synapsids. Small to large, advanced, carnivore, carnivorous, Late Pennsylvanian to Guadalupian, middle Permian "pelycosaurs". The most recent one, ''Dimetrodon angelensis'', is from the latest Kungurian or, more likely, early Roadian San Angelo Formation. However, given the notorious incompleteness of the fossil record, a recent study concluded that the Sphenacodontidae may have become extinct as recently as the early Capitanian. Primitive forms were generally small (60 cm to 1 meter), but during the later part of the Cisuralian, early Permian these animals grew progressively larger (up to 3 meters or more), to become the Apex predator, top predators of terrestrial environments. Sphenacodontid fossils are so far known only from North America and Europe. Characteristics The skull is long, deep and narrow, an adaptation for strong jaw muscles. The f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
