|
Mesenosaurus Efremovi
''Mesenosaurus'' is an extinct genus of synapsid belonging to the family Varanopidae. This genus includes two species: the type species ''Mesenosaurus romeri'' from the middle Permian (upper Kazanian) Mezen River Basin of northern Russia, and ''Mesenosaurus efremovi'' from the early Permian (Artinskian) Richards Spur locality (Oklahoma, United States). ''M. romeri''’s stratigraphic range is the middle to late Guadalupian while ''M. efremovi''’s stratigraphic range is the Cisuralian. Etymology Famous Russian paleontologist, Ivan Efremov, established ''Mesenosaurus'' as a genus. The genus name means “lizard from Mezen” while the specific epithet is given in honor of Alfred Romer. ''Mesenosaurus efremovi'' was named in honor of Ivan Efremov, who erected the genus. Description ''Mesenosaurus'' are small sized varanopid synapsids. They are characterized by mainly cranial features. Many of the postcranial features of this genus have not been analyzed fully due to a lack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and System (stratigraphy), 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 251.902 Mya. It is the sixth and 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 Perm Governorate, region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the Sauropsida, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrate Bone
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids ( reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper part of the jaw joint. The lower jaw articulates at the articular bone, located at the rear end of the lower jaw. The quadrate bone forms the lower jaw articulation in all classes except mammals. Evolutionarily, it is derived from the hindmost part of the primitive cartilaginous upper jaw. Function in reptiles In certain extinct reptiles, the variation and stability of the morphology of the quadrate bone has helped paleontologists in the species-level taxonomy and identification of mosasaur squamates and spinosaurine dinosaurs. In some lizards and dinosaurs, the quadrate is articulated at both ends and movable. In snakes, the quadrate bone has become elongated and very mobile, and contributes greatly to their ability to swallow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeothyris Florensis
''Archaeothyris'' is an extinct genus of ophiacodontid synapsid that lived during the Late Carboniferous and is known from Nova Scotia. Dated to 306 million years ago, ''Archaeothyris'', along with a more poorly known synapsid called ''Echinerpeton'', are the oldest undisputed synapsids known. The name means ''ancient window'' (Greek), and refers to the opening in the skull, the temporal fenestra, which indicates this is an early synapsid. ''Protoclepsydrops'' also from Nova Scotia is slightly older but is known by very fragmentary materials. Description ''Archaeothyris'' was more advanced than the early sauropsids, having strong jaws that could open wider than those of the early reptiles. While its sharp teeth were all of the same size & shape, it did possess a pair of enlarged canine (tooth), canines, suggesting that it was a carnivore. ''Archaeothyriss legs were articulated laterally at its pelvis and shoulders, which gave it a sprawling stance. The first toe is smaller than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiacodontidae
Ophiacodontidae is an extinct family of early synapsids from the Carboniferous and Permian. '' Archaeothyris'', and '' Clepsydrops'' were among the earliest ophiacodontids, appearing in the Late Carboniferous. Ophiacodontids are among the most basal synapsids, an offshoot of the lineage which includes therapsids and their descendants, the mammals. The group became extinct by the Kungurian or the Roadian, replaced by anomodonts, theriodonts, and the diapsid reptiles. Characteristics The lifestyle of ophiacodonts has long been controversial. Some studies suggested that they were semi-aquatic, and some even suggested a fairly aquatic lifestyle, but a recent study based on a quantitative inference model suggested that both '' Clepsydrops'' and '' Ophiacodon'' were terrestrial. Vertebral morphometric data also support, though ambiguously, a rather terrestrial lifestyle for '' Ophiacodon'', which could reach a length of . '' Archaeothyris'' may also have been terrestrial, but no ... [...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] |
Edaphosauridae
Edaphosauridae is a family of mostly large (up to or more) Late Carboniferous to Early Permian synapsids. Edaphosaur fossils are so far known only from North America and Europe. Characteristics They were the earliest known herbivorous amniotes and, along with the Diadectidae, the earliest known herbivorous tetrapods. The head is small in relation to the bulky body, and there is a tall sail along the back, which may have functioned as a thermoregulatory device. Classification The interrelationships of Edaphosauridae was investigated in details by David M. Mazierski and Robert R. Reisz (2010). The 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 ... below is modified after their phylogenetic analysis. Below is a cladogram modified from the analysis of Benson (2012): ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ianthodon Schultzei
''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 ''Ianthod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caseasauria
Caseasauria is one of the two main clades of early synapsids, the other being the Eupelycosauria. Caseasaurs are currently known only from the Late Carboniferous and the Permian, and include two superficially different families, the small insectivorous or carnivorous Eothyrididae, and the large, herbivory, herbivorous Caseidae. These two groups share a number of specialised features associated with the morphology of the snout and external nares, naris. The ancestor of caseasaurs can be traced back to an insect eating or an omnivorous reptile-like synapsid from the Pennsylvanian (geology), Pennsylvanian time of the Carboniferous, possibly resembling ''Archaeothyris'', the earliest known synapsid. The caseasaurs were abundant during the later part of the Early Permian, but by the Middle Permian caseasaur diversity declined because the group was outcompeted by the more successful therapsids. The last caseasaurs became extinct at the end of the Guadelupian (Middle Permian). Descript ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protorothyris Archeri
''Protorothyris'' is an extinct genus of Early Permian protorothyridid known from Texas and West Virginia of the United States. It was first named by Llewellyn Ivor Price in 1937 and the type species is ''Protorothyris archeri''. ''P. archeri'' is known from the holotype MCZ 1532, a three-dimensionally preserved skull and from the referred specimens, which come from four additional individuals, MCZ 2147-2150. All specimens were collected in the Cottonwood Creek site, from the Archer City Formation, Texas, dating to the Asselian stage of the Cisuralian epoch, about 299–294.6 million years ago. A second species, ''P. morani'', was first named by Alfred Sherwood Romer in 1952 with its own generic name, ''Melanothyris''. In 1973, J. Clark and Robert L. Carroll recombined ''P. morani'' as a ''Protorothyris'' species. It is known from the holotype CM 8617, a three-dimensionally preserved skull. It was collected in the Blacksville site, from the Washington Formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Captorhinus
''Captorhinus'' (from , 'to gulp down' and , 'nose') is an extinct genus of Captorhinidae, captorhinid reptiles that lived during the Permian period. Its remains are known from North America (Oklahoma, Texas) and possibly South America. Description While there are several forms of ''Captorhinus'', there are three main species that are the best known. The previously mentioned ''Captorhinus aguti'' is the type species of ''Captorhinus'', but there is also a fair amount of material collected on ''Captorhinus magnus'' and ''Captorhinus laticeps''. The most distinguishable trait of ''Captorhinus'' is its namesake: the hooking of the snout from prominent ventral angulation of the premaxillary process. Other notable characteristics include the dorsally positioned alary process of the jugal on the medial surface and flushed with the orbital margin, the retroarticular process longer anteroposteriorly than broad, and the anteriormost dentary tooth strongly procumbent. The posterior t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amniota
Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibious stem tetrapod ancestors during the Carboniferous period. Amniota is defined as the smallest crown clade containing humans, the Greek tortoise, and the Nile crocodile. Amniotes are distinguished from the other living tetrapod clade — the non-amniote lissamphibians (frogs/ toads, salamanders/newts and caecilians) — by: the development of three extraembryonic membranes ( amnion for embryonic protection, chorion for gas exchange, and allantois for metabolic waste disposal or storage); thicker and keratinized skin; costal respiration (breathing by expanding/constricting the rib cage); the presence of adrenocortical and chromaffin tissues as a discrete pair of glands near their kidneys; more complex kidneys; the presence of an astragalus for better extremity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limnoscelis Paludis
''Limnoscelis'' (/limˈnäsələ̇s/, meaning "marsh footed") was a genus of large diadectomorph tetrapods from the Late Carboniferous to early Permian of western North America. It includes two species: the type species ''Limnoscelis paludis'' from New Mexico, and ''Limnoscelis dynatis'' from Colorado, both of which are thought to have lived concurrently. No specimens of ''Limnoscelis'' are known from outside of North America. ''Limnoscelis'' was carnivorous, and likely semiaquatic, though it may have spent a significant portion of its life on land. ''Limnoscelis'' had a combination of derived amphibian and primitive reptilian features, and its placement relative to Amniota has significant implications regarding the origins of the first amniotes. Discovery and naming The type species ''Limnoscelis paludis'' was collected by the fossil hunter David Baldwin between 1877 and 1880 from the El Cobre Canyon beds of the Cutler Formation, New Mexico. Baldwin was collecting fossils i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
