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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] |
Palaeohatteria
''Palaeohatteria'' is an extinct genus of basal sphenacodonts known from the Early Permian period ( Sakmarian stage) of Saxony, Germany. It contains a single species, ''Palaeohatteria longicaudata''. Discovery ''Palaeohatteria'' is based on very young individuals including skulls and partial postcranial skeletons. All specimens were collected at Niederhäslich locality, in Dresden, from the Niederhäslich Limestone Member of the Niederhäslich Formation, Rotliegend Group ( Döhlen Basin), dating to the Sakmarian stage of the Cisuralian series, about 295.0 to 290.1 million years old. Description ''Palaeohatteria'' was a fairly small synapsid, up to 60 cm in length and with a mass of about 3 kg. The affinities of ''Palaeohatteria'' to the pelycosaur were first described in details by Alfred Sherwood Romer and Llewellyn Price (1940). They revised the taxonomy of pelycosaurs and synonymized ''Palaeohatteria'' (alongside with '' Pantelosaurus'' and others) with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacomorpha
Eupelycosauria is a large clade of animals characterized by the unique shape of their skull, encompassing all mammals and their closest extinct relatives. They first appeared 308million years ago during the Early Pennsylvanian epoch, with the fossils of ''Echinerpeton'' and perhaps an even earlier genus, ''Protoclepsydrops'', representing just one of the many stages in the evolution of mammals,Kemp. T.S., 1982, ''Mammal-like Reptiles and the Origin of Mammals''. Academic Press, New York in contrast to their earlier amniote ancestors. Taxonomy Eupelycosaurs are synapsids, animals whose skull has a single opening behind the eye. They are distinguished from the Caseasaurian synapsids by having a long, narrow supratemporal bone (instead of one that is as wide as it is long) and a frontal bone with a wider connection to the upper margin of the orbit. Laurin, M. and Reisz, R. R., 1997Autapomorphies of the main clades of synapsids- Tree of Life Web Project The only living descendant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haptodus
''Haptodus'' is an extinct genus of basal sphenacodonts, a member of the clade that includes therapsids and hence, mammals. It was at least in length. It lived in present-day France during the Early Permian. It was a medium-sized predator, feeding on insects and small vertebrates. Discovery and taxonomy ''Haptodus baylei'' ''Haptodus baylei'', the type species of ''Haptodus'', is known only from a single, badly preserved specimen hosted in the Muséum National d'Histoire Naturelle of Paris. It was collected at Les Télots, near Autun of France, from a terrestrial horizon dating to the Asselian stage of the Cisuralian series, about 299-296.4 million years old. The taxonomy of many pelycosaurs was revised in details by Alfred Sherwood Romer & Llewellyn Price (1940). They synonymized many genera, including '' Callibrachion'' (from Margenne near Autun, France), '' Datheosaurus'' (from Nowa Ruda of Poland), ''Palaeohatteria'' and '' Pantelosaurus'' (both from Germany), wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ianthodon
''Ianthodon'' is an extinct genus of basal haptodontiform synapsids from the Late Carboniferous about 304 million years ago. The taxon was discovered and named by Kissel & Reisz in 2004.Kissel, R. A. & Reisz, R. R. ''Synapsid fauna of the Upper Pennsylvanian Rock Lake Shale near Garnett, Kansas and the diversity pattern of early amniotes''. In G. Arratia, M. V. H. Wilson & R. Cloutier (eds.). ''Recent Advances in the Origin and Early Radiation of Vertebrates''. Verlag Dr. Friedrich Pfeil, 2004. The only species in the taxon, ''Ianthodon schultzei'', was found by separating it from a block that also contained the remains of ''Petrolacosaurus'' and was initially thought to contain elements of ''Haptodus''. The evolutionary significance of the taxon was not realized until a publication in 2015. The fossil of this organism was discovered in Garnett, Kansas. Description ''Ianthodon'' was first named by Kissel & Reisz in 2004; elements on the holotype slab reidentified as ''Iantho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimetrodon
''Dimetrodon'' ( or ; ) is an extinct genus of sphenacodontid synapsid that lived during the Cisuralian (Early Permian) Epoch (geology), epoch of the Permian period, around 295–272 million years ago. With most species measuring long and weighing , the most prominent feature of ''Dimetrodon'' is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It was an obligate Quadrupedalism, quadruped (it could walk only on four legs) and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the Southwestern United States, the majority of these coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, its fossils have also been found in Germany and over a dozen species have been named since the genus was first erected in 1878. ''Dimetrodon'' is often mistaken for a dinosaur or portrayed as a contemporary of dinosaurs in popular culture, but it beca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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 show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
