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Marmorerpeton Wakei
''Marmorerpeton'' is an extinct genus of prehistoric stem group-salamanders from the Middle Jurassic of the United Kingdom. They are among the oldest known salamanders. The genus was first described by Susan E. Evans et al. in 1988, when two species were named: ''M''. ''freemani'', and ''M''. ''kermacki''. The material mainly comprised disarticulated vertebrae, partial jaws, and partial skull roofing bones with heavy sculpture. It was recovered via screenwashing from the locality of Kirtlington. Previously the unit was considered to be part of the Forest Marble Formation but it is now considered part of the White Limestone Formation. ''Marmorerpeton'' is a relatively large stem-salamander, and is estimated to have reached at least , and possibly . The size of their osteocytic lacunae indicate a large genome size and some morphological characters, such as the presence of calcified cartilage in the medulla of its humerus, suggested that ''Marmorerpeton'' was neotenic. Fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Jurassic
The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations containing land animal fossils include the Forest Marble Formation in England, the Kilmaluag Formation in Scotland,British Geological Survey. 2011Stratigraphic framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf: research report RR/11/06 British Geological Survey, Keyworth, Nottingham. the Calcaire de Caen of France, the Daohugou Beds in China, the Itat Formation in Russia, the Tiouraren Formation of Niger, and the Isalo III Formation of western Madagascar. Rocks of the Middle Jurassic were formerly (until about 1980s) in Europe called ''Dogger'' or ''Brown Jurassic''. Paleogeography During the Middle Jurassic Epoch, Pangaea began to separate into Laurasia and Gond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marmorerpeton Histology
''Marmorerpeton'' is an extinct genus of prehistoric stem group-salamanders from the Middle Jurassic of the United Kingdom. They are among the oldest known salamanders. The genus was first described by Susan E. Evans et al. in 1988, when two species were named: ''M''. ''freemani'', and ''M''. ''kermacki''. The material mainly comprised disarticulated vertebrae, partial jaws, and partial skull roofing bones with heavy sculpture. It was recovered via screenwashing from the locality of Kirtlington. Previously the unit was considered to be part of the Forest Marble Formation but it is now considered part of the White Limestone Formation. ''Marmorerpeton'' is a relatively large stem-salamander, and is estimated to have reached at least , and possibly . The size of their osteocytic lacunae indicate a large genome size and some morphological characters, such as the presence of calcified cartilage in the medulla of its humerus, suggested that ''Marmorerpeton'' was neotenic. Fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Salamanders
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. The Jurassic constitutes the second and middle period of the Mesozoic Era as well as the eighth period of the Phanerozoic Eon and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province (CAMP). The beginning of the Toarcian Age started around 183 million years ago and is marked by the Toarcian Oceanic Anoxic Event, a global episode of oceanic anoxia, ocean acidification, and elevated global temperatures associated with extinctions, likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear, definitive boundary with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Salamanders
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Amphibians Of Europe
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. The Jurassic constitutes the second and middle period of the Mesozoic Era as well as the eighth period of the Phanerozoic Eon and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province (CAMP). The beginning of the Toarcian Age started around 183 million years ago and is marked by the Toarcian Oceanic Anoxic Event, a global episode of oceanic anoxia, ocean acidification, and elevated global temperatures associated with extinctions, likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear, definitive boundary with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pedicellate Teeth
Pedicellate teeth are a tooth morphology today unique to modern amphibians Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ..., but also seen in a variety of extinct labyrinthodonts. Pedicellate teeth consist of a tooth crown and a base (both composed of dentine) separated by a layer of uncalcified dentine. Pedicellate teeth fossilize better than the rest of the body, these teeth are found in Stem amphibians. The synapomorphy of modern amphibian groups is proven through the shared fossil record. References Further reading * * External links * http://palaeo.gly.bris.ac.uk/Palaeofiles/Fossilgroups/Amphibia/characters.html Amphibian anatomy {{amphibian-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kokartus
''Kokartus'' is an extinct genus of prehistoric stem-group salamander (Caudata) from the Middle Jurassic Balabansai Formation of Kyrgyzstan. The absence of clear lines of arrested growth and annuli in long bones suggests that the animals lived in an environment with stable local conditions. Like other members of Karauridae, it is thought to have been neotenic. ''Kokartus'' is thought to have fed using suction feeding via the enlargement of the buccal cavity on small fish and invertebrates, with the well developed palatal dentition (teeth on the roof of the mouth) and marginal teeth helping to grasp prey. See also * Prehistoric amphibian * List of prehistoric amphibians This list of prehistoric amphibians is an attempt to create a comprehensive listing of all genera from the fossil record that have ever been considered to be amphibians, excluding purely vernacular terms. The list includes all commonly accepted gen ... References Prehistoric salamanders Jurassic salama ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karaurus
''Karaurus'' (meaning ''head-tail'') is an extinct genus of stem-group salamander (Caudata) from the Middle to Late Jurassic (Callovian–Kimmeridgian) Karabastau Formation of Kazakhstan. It is one of the oldest salamanders known. ''Karaurus'' was large for a Jurassic salamander, about long, and very similar anatomically to modern salamanders. ''Karaurus'' is thought to have fed using suction feeding via the enlargement of the buccal cavity on small fish and invertebrates, with the well-developed palatal dentition (teeth on the roof of the mouth) and marginal teeth mandatory to grasp prey. ''Karaurus'' is thought to form a clade with ''Kokartus'' from the Middle Jurassic (Bathonian) of Kyrgyzstan, and ''Marmorerpeton'' from the Bathonian of Britain, together forming the Karauridae, which are closely related to crown salamanders. Like other members of Karauridae, ''Karaurus'' is neotenic. References Prehistoric salamanders Jurassic salamanders Late Jurassic amphibians ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karauridae
The Karauridae are a family of stem-group salamanders (Caudata) that are known from the Middle Jurassic to Early Cretaceous in Central Asia (Kazakhstan and Kyrgyzstan), Northern Asia (Siberia, Russia) and Western Europe (United Kingdom). The family includes four members: ''Karaurus'' from the Middle-Late Jurassic Karabastau Formation of Kazakhstan, ''Kokartus'' from the Middle Jurassic Balabansai Formation of Kyrgyzstan, ''Marmorerpeton'' from the Middle Jurassic Forest Marble Formation of England and Kilmaluag Formation of Scotland, and ''Kuzbassia'' from the Early Cretaceous (Aptian) Ilek Formation (Kemerovo Oblast, Russia). The members are some of the oldest known salamanders. The family is united by several morphological characters, including sculptured skull roof bones, bicapitate ribs, and an irregular interparietal seam. Like some modern salamanders, karaurids were Neoteny, neotenic. Members of the family likely fed via suction feeding on small fish and invertebrates. The Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilmaluag Formation
The Kilmaluag Formation is a Middle Jurassic geological formation in Scotland. It was formerly known as the Ostracod Limestone for preserving an abundance of fossil freshwater/low salinity ostracods. Gastropods, bivalves, trace fossil burrows, and vertebrate fossil remains have also been recorded from the formation. Vertebrate fossils include fish, crocodylomorphs, mammals, small reptiles, amphibians, theropod and sauropod dinosaurs and pterosaurs. Geology The Kilmaluag Formation was deposited during the Bathonian stage ~167 million years ago and is part of the Great Estuarine Group. Like other rock formations within the Great Estuarine Group, the Kilmaluag Formation is composed of a series of fine grained sandstones, silts, mudstones, and dolomitised limestones. The sediments were deposited in a freshwater influenced low salinity closed lagoonal palaeoenvironment subject to lagoon margin transgressions and regressions. During regressions, sediment abandonment ensued and is indic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marmorerpeton Wakei Skull Front View Jones Et Al 2022 PNAS
''Marmorerpeton'' is an extinct genus of prehistoric stem group-salamanders from the Middle Jurassic of the United Kingdom. They are among the oldest known salamanders. The genus was first described by Susan E. Evans et al. in 1988, when two species were named: ''M''. ''freemani'', and ''M''. ''kermacki''. The material mainly comprised disarticulated vertebrae, partial jaws, and partial skull roofing bones with heavy sculpture. It was recovered via screenwashing from the locality of Kirtlington. Previously the unit was considered to be part of the Forest Marble Formation but it is now considered part of the White Limestone Formation. ''Marmorerpeton'' is a relatively large stem-salamander, and is estimated to have reached at least , and possibly . The size of their osteocytic lacunae indicate a large genome size and some morphological characters, such as the presence of calcified cartilage in the medulla of its humerus, suggested that ''Marmorerpeton'' was neotenic. Fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
