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Ariekanerpeton
''Ariekanerpeton'' is an extinct genus of seymouriamorph from the lower Permian. Fossils have been found from Tajikistan representing over 900 individuals of various stages of ontogenic development. However, it is thought that none of these specimens are of fully mature animals as poor bone ossification is present and the neural arches are paired and disarticulated from the pleurocentra. ''Ariekanerpeton'' is thought to have been more closely related to ''Discosauriscus'' and ''Seymouria'' than to ''Utegenia'' due to the absence of gastralia or a postorbital-supratemporal contact. However, it is not a member of the family Discosauriscidae or the family Seymouriidae ''Seymouria'' is an extinct genus of seymouriamorph from the Early Permian of North America and Europe. Although they were amphibians (in a biological sense), ''Seymouria'' were well-adapted to life on land, with many reptilian features—so man .... There are no dermal scales present on post-metamorphic specimens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seymouriamorphs
Seymouriamorpha were a small but widespread group of limbed vertebrates (tetrapods). They have long been considered reptiliomorphs, and most paleontologists may still accept this point of view, but some analyses suggest that seymouriamorphs are stem-tetrapods (not more closely related to Amniota than to Lissamphibia). Many seymouriamorphs were terrestrial or semi-aquatic. However, aquatic larvae bearing external gills and grooves from the lateral line system have been found, making them unquestionably amphibians. The adults were terrestrial. They ranged from lizard-sized creatures (30 centimeters) to crocodile-sized 150 centimeter long animals. They were reptile-like. If seymouriamorphs are reptiliomorphs, they were the distant relatives of amniotes. Seymouriamorphs form into three main groups, Kotlassiidae, Discosauriscidae, and Seymouriidae, a group that includes the best known genus, ''Seymouria''. The last seymouriamorph became extinct by the end of the Permian. Taxonomy * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seymouriamorpha
Seymouriamorpha were a small but widespread group of limbed vertebrates (tetrapods). They have long been considered reptiliomorphs, and most paleontologists may still accept this point of view, but some analyses suggest that seymouriamorphs are stem-tetrapods (not more closely related to Amniota than to Lissamphibia). Many seymouriamorphs were terrestrial or semi-aquatic. However, aquatic larvae bearing external gills and grooves from the lateral line system have been found, making them unquestionably amphibians. The adults were terrestrial. They ranged from lizard-sized creatures (30 centimeters) to crocodile-sized 150 centimeter long animals. They were reptile-like. If seymouriamorphs are reptiliomorphs, they were the distant relatives of amniotes. Seymouriamorphs form into three main groups, Kotlassiidae, Discosauriscidae, and Seymouriidae, a group that includes the best known genus, ''Seymouria''. The last seymouriamorph became extinct by the end of the Permian. Taxonomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discosauriscidae
Discosauriscidae is a family of stegocephalians from the early Permian. They belong to the Seymouriamorpha, but their affinites to extant tetrapods are debated. They have long been considered reptiliomorph Reptiliomorpha (meaning reptile-shaped; in PhyloCode known as ''Pan-Amniota'') is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians). It was defi ...s, but some recent analyses suggest that they are stem-tetrapods. References Seymouriamorphs Cisuralian first appearances Cisuralian extinctions {{paleo-amphibian-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utegenia
''Utegenia'' is a genus of early tetrapod. It is usually regarded as a Basal (phylogenetics), basal Seymouriamorpha, seymouriamorph, but sometimes included in the Discosauriscidae or as a sister taxon of the latter. Only one species, ''Utegenia shpinari'', found from Kazakhstan, is known.Laurin, Michel. 1996. Utegenia shpinari. Version 1 January 1996. http://tolweb.org/Utegenia_shpinari/17542/1996.01.01 in The Tree of Life Web Project, http://tolweb.org/ ''Urumqia'', another basal seymouriamorph, from Urumqi, Xinjiang of China is probably a junior synonym of ''Utegenia''. References Seymouriamorphs Permian tetrapods Fossils of Kazakhstan {{paleo-amphibian-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tajikistan
Tajikistan (, ; tg, Тоҷикистон, Tojikiston; russian: Таджикистан, Tadzhikistan), officially the Republic of Tajikistan ( tg, Ҷумҳурии Тоҷикистон, Jumhurii Tojikiston), is a landlocked country in Central Asia. It has an area of and an estimated population of 9,749,625 people. Its capital and largest city is Dushanbe. It is bordered by Afghanistan to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east. It is separated narrowly from Pakistan by Afghanistan's Wakhan Corridor. The traditional homelands of the Tajiks include present-day Tajikistan as well as parts of Afghanistan and Uzbekistan. The territory that now constitutes Tajikistan was previously home to several ancient cultures, including the city of Sarazm of the Neolithic and the Bronze Age and was later home to kingdoms ruled by people of different faiths and cultures, including the Oxus civilization, Andronovo culture, Buddhism, Nestorian Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontogenic
Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the study of the entirety of an organism's lifespan. Ontogeny is the developmental history of an organism within its own lifetime, as distinct from phylogeny, which refers to the evolutionary history of a species. Another way to think of ontogeny is that it is the process of an organism going through all of the developmental stages over its lifetime. The developmental history includes all the developmental events that occur during the existence of an organism, beginning with the changes in the egg at the time of fertilization and events from the time of birth or hatching and afterward (i.e., growth, remolding of body shape, development of secondary sexual characteristics, etc.). While developmental (i.e., ontogenetic) processes can influence sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discosauriscus
''Discosauriscus'' was a small seymouriamorph which lived in what is now Central and Western Europe in the Early Permian Period. Its best fossils have been found in the Broumov and Bačov Formations of Boskovice Furrow, in the Czech Republic. Classification ''Discosauriscus'' belongs to the order Seymouriamorpha, and is the type genus of the family Discosauriscidae. Currently recognised are two valid species - ''Discosauriscus austriacus'' and ''Discosauriscus pulcherrimus''. ''Letoverpeton'' is a junior synonym of ''Discosauriscus''. Characteristics Discosauriscids were long thought to be known from larval or neotenic forms, and three ontogenetic stages had been distinguished.Klembara, Jozef. 1996. Discosauriscus. Version 1 January 1996. http://tolweb.org/Discosauriscus/17544/1996.01.01 in The Tree of Life Web Project, http://tolweb.org/ However, more recent studies concluded that some subadult, probably terrestrial specimens were known, so the case for neoteny in this ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seymouria
''Seymouria'' is an extinct genus of seymouriamorph from the Early Permian of North America and Europe. Although they were amphibians (in a biological sense), ''Seymouria'' were well-adapted to life on land, with many reptilian features—so many, in fact, that ''Seymouria'' was first thought to be a primitive reptile. It is primarily known from two species, ''Seymouria baylorensis'' and ''Seymouria sanjuanensis''. The type species, ''S. baylorensis'', is more robust and specialized, though its fossils have only been found in Texas. On the other hand, ''Seymouria sanjuanensis'' is more abundant and widespread. This smaller species is known from multiple well-preserved fossils, including a block of six skeletons found in the Cutler Formation of New Mexico, and a pair of fully grown skeletons from the Tambach Formation of Germany, which were fossilized lying next to each other. For the first half of the 20th century, ''Seymouria'' was considered one of the oldest and most "prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s). Article 67.1 A similar concept is used for suprageneric groups and called a type genus. In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen (or, rarely, an illustration) which is also the type of a species name. The species name that has that type can also be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have such types. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastralia
Gastralia (singular gastralium) are dermal bones found in the ventral body wall of modern crocodilians and tuatara, and many prehistoric tetrapods. They are found between the sternum and pelvis, and do not articulate with the vertebrae. In these reptiles, gastralia provide support for the abdomen and attachment sites for abdominal muscles. The possession of gastralia may be ancestral for Tetrapoda and were possibly derived from the ventral scales found in animals like rhipidistians, labyrinthodonts, and ''Acanthostega'', and may be related to ventral elements of turtle plastrons. Similar, but not homologous cartilagenous elements, are found in the ventral body walls of lizards and anurans. These structures have been referred to as inscriptional ribs, based on their alleged association with the inscriptiones tendinae (the tendons that form the six pack in humans). However, the terminology for these gastral-like structures remains confused. Both types, along with sternal ribs ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postorbital
The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some vertebrates, the postorbital is fused with the postfrontal to create a postorbitofrontal. Birds have a separate postorbital as an embryo, but the bone fuses with the frontal Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * ''The Front'', 1976 film Music * The Front (band), an American rock band signed to Columbia Records and active in the 1980s and e ... before it hatches. References * Roemer, A. S. 1956. ''Osteology of the Reptiles''. University of Chicago Press. 772 pp. Skull {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supratemporal
The supratemporal bone is a paired cranial bone present in many tetrapods and tetrapodomorph fish. It is part of the temporal region (the portion of the skull roof behind the eyes), usually lying medial (inwards) relative to the squamosal and lateral (outwards) relative to the parietal and/or postparietal. It may also contact the postorbital or intertemporal (which lie forwards), or tabular (which lies backwards), when those bones are present. The supratemporal is a common component of the skull in many extinct amphibians, though it is apparently absent in the lightweight skulls of living lissamphibians (frogs and salamanders). Embryological studies of salamanders suggests that the supratemporal fuses with the squamosal in early development. A separate supratemporal was retained by early synapsids and reptiles, but was strongly reduced in many groups. Squamates (lizards and snakes) still possess a small supratemporal, though archosaurs (crocodilians and birds) and mammals lack i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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