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Varanopidae
Varanopidae is an extinct family of amniotes that resembled monitor lizards and may have filled a similar niche, hence the name. Typically, they are considered synapsids that evolved from an '' Archaeothyris''-like synapsid in the Late Carboniferous. However, some recent studies have recovered them being taxonomically closer to diapsid reptiles. A varanopid from the latest Middle Permian ''Pristerognathus'' Assemblage Zone is the youngest known varanopid and the last member of the "pelycosaur" group of synapsids. Description No known varanopids developed a sail like ''Dimetrodon''. The length of known varanopids, including the tail, varies from . Varanopids already showed some advanced characteristics of true pelycosaurs such as their deep, narrow, elongated skulls. Their jaws were long and their teeth were sharp. However, they were still primitive by mammalian standards. They had long tails, lizard-like bodies, and thin legs. The varanopids were mostly carnivorous, but as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varanopidae
Varanopidae is an extinct family of amniotes that resembled monitor lizards and may have filled a similar niche, hence the name. Typically, they are considered synapsids that evolved from an '' Archaeothyris''-like synapsid in the Late Carboniferous. However, some recent studies have recovered them being taxonomically closer to diapsid reptiles. A varanopid from the latest Middle Permian ''Pristerognathus'' Assemblage Zone is the youngest known varanopid and the last member of the "pelycosaur" group of synapsids. Description No known varanopids developed a sail like ''Dimetrodon''. The length of known varanopids, including the tail, varies from . Varanopids already showed some advanced characteristics of true pelycosaurs such as their deep, narrow, elongated skulls. Their jaws were long and their teeth were sharp. However, they were still primitive by mammalian standards. They had long tails, lizard-like bodies, and thin legs. The varanopids were mostly carnivorous, but as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapsids
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 pelycosau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascendonanus
''Ascendonanus'' (meaning "climbing dwarf") is an extinct genus of varanopid amniote from the Early Permian of Germany. It is one of the earliest specialized arboreal (tree-living) tetrapods currently known and outwardly resembled a small lizard. The animal was about 40 cm long, with strongly curved claws, short limbs, a slender, elongated trunk, and a long tail. It would have preyed on insects and other small arthropods. The taxonomic position of varanopids is currently debated between synapsids (related to mammals, the most widely accepted idea) and diapsids (related to reptiles). The fossils of ''Ascendonanus'' are of special scientific importance because they include remains of skin, scales, scutes, bony ossicles, and soft-tissue body outlines, which could indicate that some of the oldest relatives of mammals had a scaly "reptilian-type" appearance. The related small varanopid ''Eoscansor'', recently described from New Mexico, was also adapted to climbing, very likel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerosaurus Wellesi 4
''Aerosaurus'' (meaning "copper lizard") is an extinct genus within Varanopidae, a family of non-mammalian synapsids. It lived between 252-299 million years ago during the Early Permian in North America. The name comes from Latin ''aes'' (''aeris'') (combining stem: ''aer''-) “copper” and Greek ''sauros'' “lizard,” for El Cobre Canyon (from Spanish ''cobre'' “copper”) in northern New Mexico, where the type fossil was found and the site of former copper mines. ''Aerosaurus'' was a small to medium-bodied carnivorous synapsid characterized by its recurved teeth, triangular lateral temporal fenestra, and extended teeth row. Two species are recognized: ''A. greenleeorum'' (1937) and ''A. wellesi'' (1981). History and discovery ''Aerosaurus'' was a taxon named by American paleontologist and biologist Alfred Romer in 1937. There have only been two species named: ''A. greenleeorum'' (1937) and ''A. wellesi'' (1981), both discovered in New Mexico. ''A. greenleeorum'' Romer, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heleosaurus
''Heleosaurus scholtzi'' is an extinct species of basal synapsids, known as pelycosaurs, in the family of Varanopidae during the middle Permian.Reisz, R. R. & Modesto, S. P. 2007. ''Heleosaurus scholtzi'' from the Permian of South Africa: a varanopid synapsid, not a diapsid reptile. ''Journal of Vertebrate Paleontology'' 27 (3): 734-739. At first ''H. scholtzi'' was mistakenly classified as a diapsid. Members of this family were carnivorous and had dermal armor, and somewhat resembled monitor lizards. This family was the most geologically long lived, widespread, and diverse group of early amniotes. To date only two fossils have been found in the rocks of South Africa.Broom, R. "On Some New Fossil Reptiles from the Karroo Beds of Victoria West, South Africa." ''Transactions of the South African Philosophical Society'' 18 (1907): 31-42. Taylor and Francis Online. Web. Botha-Brink, Jennifer. "A Mixed-Age Classed 'Pelycosaur' Aggregation from South Africa: Earliest Evidence of Parental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesenosaurus And Varanodon
''Mesenosaurus'' is an extinct genus of amniote. It belongs 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, and named it after its roots with the (literal translation is “lizard from Mezen”). ''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 of fossil evide ... [...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. Rept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varanops Brevirostris
''Varanops'' is an extinct genus of Early Permian varanopid synapsids known from Texas and Oklahoma of the United States. It was first named by Samuel Wendell Williston in 1911 as a second species of '' Varanosaurus'', ''Varanosaurus brevirostris''. In 1914, Samuel W. Williston reassigned it to its own genus and the type species is ''Varanops brevirostris''. Discovery ''V. brevirostris'' is known from the holotype FMNH UC 644, a three-dimensionally preserved nearly complete and articulated skeleton including a nearly complete skull and mandibles. It was collected in the Indian Creek, 35 site (=''Cacops'' Bonebed), from the Arroyo Formation of the Clear Fork Group, Baylor County of Texas, dating to the early Kungurian stage of the Cisuralian Epoch, about 279.5-272.5 million years ago. Many well preserved specimens from the same locality and horizon of the type specimen, including FMNH UR 2423, nearly complete skull and mandibles, MCZ 1926, compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoscansor
''Eoscansor'' (EE-oh-SKAN-sor; meaning "dawn climber") is a species of small Varanopidae, varanopid amniote that lives from the upper Pennsylvanian (geology), Pennsylvanian subperiod in northern New Mexico, New Mexico, United States 305 million years ago. The species ''Eoscansor cobrensis'' was 24.5 centimeters (9.6 inches) long and weighed 58.3 grams. The tetrapods teeth indicated that it was insectivorous. The small size and grasping limbs means that was ''E. cobrensis'' highly agile and likely Arboreal locomotion, arboreal (tree climbing). The name ''Eoscansor'' means "dawn climber", derived from Greek language, Greek with "Eo" meaning dawn and "scansor" meaning climber. ''E. cobrensis'' is currently the oldest specialised climbing tetrapod animal pushing back the original record by 15 million years. The species was discovered in the El Cobre Canyon Formation in northern New Mexico near the village of Chama, New Mexico, Chama in 2005 but was not prepared until 2015. The COVID-19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amniotes
Amniotes are a clade of tetrapod vertebrates that comprises sauropsids (including all reptiles and birds, and extinct parareptiles and non-avian dinosaurs) and synapsids (including pelycosaurs and therapsids such as mammals). They are distinguished from the other tetrapod clade — the amphibians — by the development of three extraembryonic membranes ( amnion for embryoic protection, chorion for gas exchange, and allantois for metabolic waste disposal or storage), thicker and more keratinized skin, and costal respiration (breathing by expanding/constricting the rib cage). All three main features listed above, namely the presence of an amniotic buffer, water-impermeable cutes and a robust respiratory system, are very important for amniotes to live on land as true terrestrial animals – the ability to reproduce in locations away from water bodies, better homeostasis in drier environments, and more efficient air respiration to power terrestrial locomotions, althou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pristerognathus Assemblage Zone
The ''Pristerognathus'' Assemblage Zone is a tetrapod assemblage zone or biozone which correlates to the upper Abrahamskraal Formation and lowermost Teekloof Formation, Adelaide Subgroup of the Beaufort Group, a fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa. The thickest outcrops, reaching not more than , occur just east of Sutherland through to Beaufort West in the south and Victoria West in the north. Exposures are also found west of Colesberg and south of Graaff-Reinet. The '' Pristerognathus'' Assemblage Zone is the third biozone of the Beaufort Group. The name of the biozone refers to ''Pristerognathus polyodon'', a medium-sized carnivorous therocephalian therapsid. It is characterized by the presence of this therocephalian species in association with '' Diictodon feliceps'', a small, fossorial dicynodont whose fossils are especially common in this biozone. History The first fossils to be found in the Beaufort Group roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeothyris
''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 canines, suggesting that it was a carnivore. Archaeothyris' legs were articulated laterally at its pelvis and shoulders, which gave it a sprawling stance. The first toe is smaller than the second. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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