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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 thickening of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimetrodon
''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontidae. The most prominent feature of ''Dimetrodon'' is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It walked 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 coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, its fossils have been found in Germany. Over a dozen species have been named since the genus was first erected in 1878. ''Dimetrodon'' is often mistaken for a dinosaur or as a contemporary of dinosaurs in popular culture, but it became extinct some 40 million years before the first appearance of dinosaurs. Reptile-li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodontidae
Sphenacodontidae (Greek: "wedge point tooth family") is an extinct family of small to large, advanced, carnivorous, Late Pennsylvanian to middle Permian pelycosaurs. The most recent one, ''Dimetrodon angelensis'', is from the late Kungurian or 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 early Permian these animals grew progressively larger (up to 3 meters or more), to become the top predators of their 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 front teeth are large and dagger-like, whereas the teeth in the sides and rear of the jaw are much smaller (hence the name of the well-kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kenomagnathus
''Kenomagnathus'' (meaning "gap jaw", in reference to the diastema in its upper tooth row) is a genus of synapsid belonging to the Sphenacodontia, which lived during the Pennsylvanian subperiod of the Carboniferous in what is now Garnett, Kansas, United States. It contains one species, ''Kenomagnathus scottae'', based on a specimen consisting of the maxilla and lacrimal bones of the skull, which was catalogued as ROM 43608 and originally classified as belonging to '' "Haptodus" garnettensis''. Frederik Spindler named it as a new genus in 2020. Discovery and naming Norman Newell discovered a fossil locality near Garnett, Kansas, United States in 1931, belonging to the Rock Lake Member of the Stanton Formation. Around 1932, Henry Lane and Claude Hibbard had collected a variety of animal and plant fossils from the locality. Among these were skeletons of ''Petrolacosaurus'', which were subsequently described in 1952 by Frank Peabody. Hoping to find more material, a field team from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 concerninproportions of the bones of the skull and the teeth The sphenacodontoids evolved from earlier sphenacodonts such as ''Haptodus'' via a number of transitional stages of small, unspecialised pelycosaurs. Classification The following taxonomy follows Fröbisch ''et al.'' (2011) and Benson (2012) unless otherwise noted. Class Synapsida * Sphenacodontoidea ** Family †Sphenacodontidae ** Therapsida See also * Evolution of mammals References * Laurin, M. and Reisz, R. R., 1997Autapomorphies of the main clades of synapsids- Tree of Life Web Project The Tree of Life Web Project is an Internet project providing information about the diversity and phylogeny of life on Earth. This collaborative peer reviewed project began in 1995 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapsid
Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptiles and birds. The group includes mammals and every animal more closely related to mammals than to sauropsids. Unlike other amniotes, synapsids have a single temporal fenestra, an opening low in the skull roof behind each eye orbit, leaving a bony arch beneath each; this accounts for their name. The distinctive temporal fenestra developed about 318 million years ago during the Late Carboniferous period, when synapsids and sauropsids diverged, but was subsequently merged with the orbit in early mammals. Traditionally, non-mammalian synapsids were believed to have evolved from reptiles, and therefore described as mammal-like reptiles in classical systematics, and primitive synapsids were also referred to as pelycosaurs, or pelycosaur-gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodon Ferox
''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related ''Dimetrodon'', ''Sphenacodon'' was a carnivorous member of the Eupelycosauria family Sphenacodontidae. However, ''Sphenacodon'' had a low crest along its back, formed from blade-like bones on its vertebrae (neural spines) instead of the tall dorsal sail found in ''Dimetrodon''. Fossils of ''Sphenacodon'' are known from New Mexico and the Utah–Arizona border region in North America. Researchers currently recognize two species: ''Sphenacodon ferox'' (the type species) and ''Sphenacodon ferocior''. ''Sphenacodon ferocior'' can be up to 40% larger in overall size (at about long) compared to ''Sphenacodon ferox'' (at about ). In addition, the dorsal spines in ''Sphenacodon ferocior'' are proportionately 45% taller than in ''Sphenacodon ferox''. The recent discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeohatteriidae
Palaeohatteriidae is an extinct family of basal sphenacodonts known from the Early Permian period (Asselian-Sakmarian stages) of Saxony, Germany.Spindler, F. 2016. Morphological description and taxonomic status of (Synapsida: Sphenacodontia). ''Freiberger Forschungshefte'' C550(23): 1–57. https://www.researchgate.net/publication/321129043_Morphological_description_and_taxonomic_status_of_Palaeohatteria_and_Pantelosaurus_Synapsida_Sphenacodontia Two genera are known: ''Palaeohatteria'' and ''Pantelosaurus''.Friedrich von Huene (1925). "Ein neuer Pelycosaurier aus der unteren Permformaiton Sachens". ''Geologische und Paläontologische Abhandlungen''. 18: 215–264. Classification The cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... below shows the phylogenetic position ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraceratops
''Tetraceratops insignis'' ("four-horned face emblem") is an extinct synapsid from the Early Permian that was formerly considered the earliest known representative of Therapsida, a group that includes mammals and their close extinct relatives. It is known from a single skull, discovered in Texas in 1908. According to a 2020 study, it should be classified as a primitive non-therapsid sphenacodont rather than a genuine basal therapsid. Description ''Tetraceratops'' is known from a single skull discovered in Texas in the early 1900s. Contrary to its genus name, ''Tetraceratops'' actually has six horns, one pair being on the premaxilla bones, one pair on the prefrontal bones, and one pair on the angular processes of the mandible. When it was discovered and described in 1908, the skull was still embedded in a matrix, and only the premaxilla and prefrontal pairs were visible. In life, thus, it would have resembled a large lizard with four horns on its snout, and a pair of large s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shashajaia
''Shashajaia'' is a genus of extinct non-mammalian synapsids from the late Carboniferous to Early Permian. It was one of the earliest members of the group, coming from the Gzhelian stage. It lived in what is now the Halgaito Formation within the larger Cutler group located in the U.S state of Utah. According to a description study, this synapsid is known from well preserved dentary and jaw fragments. ''Shashajaia'' shares many similarities to other sphenacodontids including, enlarged ( canine-like) anterior dentary teeth, a dorsoventrally deep symphysis and low-crowned, subthecodont postcanines having festooned plicidentine. The study also found that this genus is close to the evolutionary divergence of the Sphenacodontids and the Therapsids, from which mammalian synapsids (including humans) arose from. Based on studies done on its teeth, Paleontologists found that as their prey became more terrestrial, synapsids like ''Shashajaia'' adapted to life on land and grew larger teeth to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haptodus Baylei
''Haptodus'' is an extinct genus of basal (phylogenetics), basal sphenacodont, 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 history ''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 (stratigraphy), series, about 299-296.4 million years ago, 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), ''Palaeohatte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haptodus
''Haptodus'' is an extinct genus of basal sphenacodont, 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 history ''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), with ''Haptod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids ( reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
