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Varanopidae
Varanopidae is an extinct family (biology), family of amniotes known from the Late Carboniferous to Middle Permian that resembled monitor lizards (with the name of the group deriving from the monitor lizard genus ''Varanus'') and may have filled a similar niche. Typically, they are considered to be relatively Basal (phylogenetics), basal Synapsida, synapsids (and thus more closely related to mammals than to reptiles), although some studies from the late 2010s recovered them being taxonomically closer to diapsid reptiles, recent studies from the early 2020s support their traditional placement as synapsids on the basis of high degree of bone labyrinth ossification, maxillary canal morphology and phylogenetic analyses. A varanopid from the late Middle Permian Pristerognathus Assemblage Zone, ''Pristerognathus'' Assemblage Zone (Capitanian) is the youngest known varanopid and the last member of the "pelycosaur" group of synapsids. Thus, Varanopidae vanishes from the fossil record at th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapsida
Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant reptiles and therefore, birds). Unlike other amniotes, synapsids have a single temporal fenestra, an opening low in the skull roof behind each eye socket, leaving a bony arch beneath each; this accounts for the name "synapsid". 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. The basal amniotes ( reptiliomorphs) from which synapsids evolved were historically simply called "reptiles". Therefore, stem group synapsids were then described as mammal-like reptiles in classical systematics, and non- therapsid synapsids were also referred to as pelycosaurs or pelycosaur- grade syn ... [...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 likely i ... [...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 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] |
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] |
Varanops Brevirostris
''Varanops'' is an extinct genus of Early Permian varanopid 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 to 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, complete skull a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoscansor
''Eoscansor'' (EE-oh-SKAN-sor; meaning "dawn climber") is a species of small varanopid amniote that lives from the upper Pennsylvanian subperiod in northern 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 (tree climbing). The name ''Eoscansor'' means "dawn climber", derived from Greek "Eos" meaning dawn and Latin "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 in 2005 but was not prepared until 2015. The COVID-19 pandemic in 2020 pushed study back until 2022 where it was described as a new genus and species. '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diapsid
Diapsids ("two arches") are a clade of sauropsids, distinguished from more primitive eureptiles by the presence of two holes, known as temporal fenestrae, in each side of their skulls. The earliest traditionally identified diapsids, the araeoscelidians, appeared about three hundred million years ago during the late Carboniferous period. All diapsids other than the most primitive ones in the clade Araeoscelidia are often placed into the clade Neodiapsida. The diapsids are extremely diverse, and include birds and all modern reptile groups, including turtles, which were historically thought to lie outside the group. All modern reptiles and birds are placed within the neodiapsid subclade Sauria. Although some diapsids have lost either one hole (lizards), or both holes (snakes and turtles), or have a heavily restructured skull (modern birds), they are still classified as diapsids based on their ancestry. At least 17,084 species of diapsid animals are extant: 9,159 birds, and 7,925 s ... [...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.Rubidge, B. S. (ed.) 1995b. ''Biostratigraphy of the Beaufort Group (Karoo Supergroup).'' South African Committee of Stratigraphy. ''Biostratigraphic Series 1''. Pretoria, Council for Geoscience. The name of the biozone refers to '' Pristerognathus polyodon'', a medium-sized carnivorous therocephalian therapsid. It is characterized by the presence of this therocephalian spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amniotes
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 ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
