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Embolomeres
Embolomeri is an order of tetrapods or stem-tetrapods, possibly members of Reptiliomorpha. Embolomeres first evolved in the Early Carboniferous ( Mississippian) Period and were the largest and most successful predatory tetrapods of the Late Carboniferous ( Pennsylvanian) Period. They were specialized semiaquatic predators with long bodies for eel-like undulatory swimming. Embolomeres are characterized by their vertebral centra, which are formed by two cylindrical segments, the pleurocentrum at the rear and intercentrum at the front. These segments are equal in size. Most other tetrapods have pleurocentra and intercentra which are drastically different in size and shape. Embolomeres were among the earliest large carnivorous tetrapods, with members such as the crocodilian-like ''Proterogyrinus'' appearing in the Visean stage of the Carboniferous. They declined in diversity during the Permian period, though at least one representative ('' Archeria)'' was common in the Early Permian. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippian Age
The Mississippian ( ), also known as Lower Carboniferous or Early Carboniferous, is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from roughly 358.9 to 323.2 million years ago. As with most other geochronologic units, the rock beds that define the Mississippian are well identified, but the exact start and end dates are uncertain by a few million years. The Mississippian is so named because rocks with this age are exposed in the Mississippi Valley. The Mississippian was a period of marine transgression in the Northern Hemisphere: the sea level was so high that only the Fennoscandian Shield and the Laurentian Shield were dry land. The cratons were surrounded by extensive delta systems and lagoons, and carbonate sedimentation on the surrounding continental platforms, covered by shallow seas. In North America, where the interval consists primarily of marine limestones, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Osteology Of The Reptiles P98
''The'' is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pronoun ''thee' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepospondyli
Lepospondyli is a diverse clade of early tetrapods. With the exception of one late-surviving lepospondyl from the Late Permian of Morocco ('' Diplocaulus minimus''), lepospondyls lived from the Visean stage of the Early Carboniferous to the Early Permian and were geographically restricted to what is now Europe and North America. Five major groups of lepospondyls are known: Adelospondyli; Aïstopoda; Lysorophia; Microsauria; and Nectridea. Lepospondyls have a diverse range of body forms and include species with newt-like, eel- or snake-like, and lizard-like forms. Various species were aquatic, semiaquatic, or terrestrial. None were large (the biggest genus, the diplocaulid '' Diplocaulus'', reached a meter in length, but most were much smaller), and they are assumed to have lived in specialized ecological niches not taken by the more numerous temnospondyl amphibians that coexisted with them in the Paleozoic. Lepospondyli was named in 1888 by Karl Alfred von Zittel, who coi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthracosaurus
''Anthracosaurus'' is an extinct genus of embolomere that lived during the Late Carboniferous (around 315 million years ago) in what is now Scotland, England, and Ohio. Measuring around long, it was a large, aquatic eel-like predator. It has a robust skull about in length with large teeth in the jaws and on the roof of the mouth. ''Anthracosaurus'' probably inhabited swamps, rivers and lakes. Its name is Greek for "coal lizard". Discovery and specimens Scotland The genus and type species ''Anthracosaurus russelli'' were named by Thomas Henry Huxley in 1863, based on fossils acquired by mining surveyor James Russell in 1861. Nearly all fossils were found near Airdrie, in the historic County Lanarkshire of Scotland. Geologically speaking, they hail from the Blackband Ironstone of the Scottish Middle Coal Measures. In traditional European stratigraphy, this layer would be dated to the Westphalian B, corresponding to the early-middle part of the Pennsylvanian (Late Carb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chroniosuchia
Chroniosuchia is a group of tetrapods that lived from the Middle Permian to Late Triassic in what is now Kyrgyzstan, China and Germany, Eastern Europe. Chroniosuchians are often thought to be reptiliomorphs, but some recent phylogenetic analyses suggest instead that they are stem-tetrapods. They were all rather short limbed with a strong tail and elongated snout, somewhat resembling modern crocodiles. The group is traditionally considered to be a suborder or order of labyrinthodonts. Chroniosuchians likely had ecological niches as riverside predators, and may have been outcompeted by semiaquatic true reptiles such as phytosaurs in the late Triassic. Most forms bore a heavy armour of scutes along the back, possibly for protection against land born predators like therapsids, or to strengthen the axial skeleton for terrestrial locomotion. Indeed, femoral microanatomy of '' Chroniosaurus'' suggests that it was amphibious to terrestrial. Description The most distinguishing features ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silvanerpeton
''Silvanerpeton'' is an extinct genus of early reptiliomorph found by Stan Wood in the East Kirkton Quarry of West Lothian, Scotland, in a sequence from the Brigantian substage of the Viséan ( Lower Carboniferous). The find is important, as the quarry represents terrestrial deposits from Romer's gap, a period poor in fossils where the higher groups "labyrinthodonts" evolved. The type species ''Silvanerpeton miripedes'' was named by Jennifer A. Clack in 1993/1994. The generic name is derived from Silvanus, the Roman god of woods. The specific name means "wondrous feet" in Latin. The holotype is specimen UMZC T1317, a skeleton with skull and skin impressions. Description In life ''Silvanerpeton'' was about 40 cm (1 ft) long. Some paleontologists think it was semi-aquatic as an adult, others believe only young individuals of ''Silvanerpeton'' were aquatic and the adults were fully terrestrial. Classification Based on a remarkably well preserved humerus and other tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoherpeton
''Eoherpeton'' is the only genus of the family Eoherpetontidae in the extinct suborder Embolomeri. It is known from the Visean and Namurian (now Serpukhovian and lower Bashkirian) stages of the Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ... of Scotland. References Embolomeri Mississippian sarcopterygians of Europe Fossil taxa described in 1975 {{paleo-tetrapodomorph-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Most Recent Common Ancestor
A most recent common ancestor (MRCA), also known as a last common ancestor (LCA), is the most recent individual from which all organisms of a set are inferred to have descended. The most recent common ancestor of a higher taxon is generally assumed to have been a species. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms. The ancestry of a set of individuals can sometimes be determined by referring to an established pedigree, although this may refer only to patrilineal or matrilineal lines for sexually-reproducing organisms with two parents, four grandparents, etc. However, in general, it is impossible to identify the exact MRCA of a large set of individuals, but an estimate of the time at which the MRCA lived can often be given. Such ''time to most recent common ancestor'' (''TMRCA'') estimates can be given based on DNA test results and established mutation rates as practiced in genetic genealogy, or by reference to a non- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michel Laurin
Michel Laurin is a Canadian-born French vertebrate paleontologist whose specialities include the emergence of a land-based lifestyle among vertebrates, the evolution of body size and the origin and phylogeny of lissamphibians. He has also made important contributions to the literature on phylogenetic nomenclature. As an undergraduate, he worked in the laboratory of Robert L. Carroll and earned his Ph.D. at the University of Toronto under the direction of Robert R. Reisz; his thesis concerned the osteology of Seymouriamorpha, seymouriamorphs. His 1991 review of diapsid phylogeny provided the broadest review of the subject up to that date. In 1995, Laurin and Reisz coauthored a widely cited article providing evidence that the synapsids are the sister group of all other amniotes. He later worked on untangling the phylogeny of the Stegocephalia, a group with a notoriously difficult phylogeny. He later moved to France; since 1998, he has been a CNRS researcher at the Muséum National d'H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas
Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the west, and has Mexico-United States border, an international border with the Mexican states of Chihuahua (state), Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south and southwest. Texas has Texas Gulf Coast, a coastline on the Gulf of Mexico to the southeast. Covering and with over 31 million residents as of 2024, it is the second-largest state List of U.S. states and territories by area, by area and List of U.S. states and territories by population, population. Texas is nicknamed the ''Lone Star State'' for its former status as the independent Republic of Texas. Spain was the first European country to Spanish Texas, claim and control Texas. Following French colonization of Texas, a short-lived colony controlled by France, Mexico ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Beds Of Texas And Oklahoma
The Red Beds of Texas and Oklahoma are a group of Early Permian-age geologic strata in the southwestern United States cropping out in north-central Texas and south-central Oklahoma. They comprise several stratigraphic groups, including the Clear Fork Group, the Wichita Group, and the Pease River Group.Nelson, John W., Robert W. Hook, and Dan S. Chaney (2013)Lithostratigraphy of the Lower Permian (Leonardian) Clear Fork Formation of North-Central Texasfrom The Carboniferous-Permian Transition: Bulletin 60, ed. Spencer G. Lucas et al. New Mexico Museum of Natural History and Science, pg. 286-311. Retrieved December 28, 2017. The Red Beds were first explored by American paleontologist Edward Drinker Cope starting in 1877.Cope, E.D. (1878)Descriptions of Batrachia and Reptilia from the Permian Formation of Texas.Proceedings of the American Philosophical Society, vol. 17, no. 101, pg. 505-30. Retrieved December 28, 2017. Fossil remains of many Permian tetrapods (four-limbed vertebrates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cricotus
''Cricotus'' is an extinct genus of Embolomeri. It was erected by Cope in 1875, on the basis of fragmentary, not clearly associated remains including caudal vertebrae, on which the name was established (in fact, based on a single intercentrum), as well as a few other postcranial bones. It was little-used in the subsequent literature, contrary to '' Archeria'', which appears to be a junior synonym of ''Cricotus''. However, given that the type species of ''Cricotus'' (''C. heteroclitus'') is a ''nomen dubium'', the name ''Cricotus'' is unavailable. This led to HolmesHolmes R. 1989The skull and axial skeleton of the Lower Permian anthracosauroid amphibian''Archeria crassidisca'' Cope. Palaeontographica Abt. A Palaeozoologie – Stratigraphie 207: 161-206. suggesting using the name '' Archeria'' for this taxon, though he provided no evidence that he made a formal appeal to the International Commission on Zoological Nomenclature The International Commission on Zoological Nomenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
