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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] |
Archeria (animal Genus)
''Archeria'' is a genus of embolomere which lived in the Early Permian of Texas and Oklahoma. It was a medium-sized aquatic predator, with an elongated body and tail. The limbs were proportionally small but well-developed, connected to robust limb girdles. The skull was moderately long and low, up to 30 cm (12 inches) in length. Unlike most embolomeres, ''Archeria'' had many small chisel-shaped teeth instead of large fangs. The anatomy of ''Archeria'' is well known compared to most embolomeres, as it is known from multiple complete skeletons discovered in 1939 by A.S. Romer. These specimens hailed from the Geraldine bonebed, a deposit of the coastal Admiral Formation in Archer County, Texas. Other remains of the genus were previously referred to ''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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archeria (animal)
''Archeria'' is a genus of embolomere which lived in the Early Permian of Texas and Oklahoma. It was a medium-sized aquatic predator, with an elongated body and tail. The limbs were proportionally small but well-developed, connected to robust limb girdles. The skull was moderately long and low, up to 30 cm (12 inches) in length. Unlike most embolomeres, ''Archeria'' had many small chisel-shaped teeth instead of large fangs. The anatomy of ''Archeria'' is well known compared to most embolomeres, as it is known from multiple complete skeletons discovered in 1939 by A.S. Romer. These specimens hailed from the Geraldine bonebed, a deposit of the coastal Admiral Formation in Archer County, Texas. Other remains of the genus were previously referred to ''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 fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthracosaurus
''Anthracosaurus'' is an extinct genus of embolomere, a possible distant relative of reptiles that lived during the Late Carboniferous (around 310 million years ago) in what is now Scotland and England. It was a large, aquatic eel-like predator able to grow up to in length. 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". The genus was named by Thomas Henry Huxley Thomas Henry Huxley (4 May 1825 – 29 June 1895) was an English biologist and anthropologist specialising in comparative anatomy. He has become known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution. The storie ... when James Russell, a mining surveyor, sent him the first specimens. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterogyrinus
''Proterogyrinus'' is an extinct genus of early tetrapods from the order Embolomeri. Fossil remains of ''Proterogyrinus'' have been found in Scotland, UK, and West Virginia, United States, and date back to the Serpukhovian (mid-Carboniferous period), which is from about 331 to 323 million years ago. The genus was originally named by renowned vertebrate paleontologist Alfred Sherwood Romer in 1970. A comprehensive redescription was later published by Canadian paleontologist Robert Holmes in 1984. The generic name "''Proterogyrinus''" is Greek for "earlier wanderer" or "earlier tadpole". This name was chosen by Romer in keeping with a trend of naming long-bodied early tetrapods (such as ''Eogyrinus'' and ''Crassigyrinus'') with the suffix "-''gyrinus''". Romer hesitated from designating ''Proterogyrinus'' as a true embolomere, because its intercentra (the forward portion of each vertebra) were smaller than its pleurocentra (the rear portion). He used the group Anthracosauria to enc ... [...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 period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ... of Scotland. References External linksThe skull of ''Eoherpeton'', from the original description Embolomeres< ... [...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 is why Holmes Holmes R. 1989The skull and axial skeleton of the Lower Permian anthracosauroid amphibian''Archeria crassidisca'' Cope. Palaeontographica Abt. A Palaeozoologie – Stratigraphie 207: 161-206. suggested 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 Nomenclat ... [...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 is treate ... [...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 Group (stratigraphy), 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- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rachitomi
The Rachitomi were a group of extinct Palaeozoic labyrinthodont amphibians, according to an earlier classification system.Kent, G.C. & Miller, L. (1997): Comparative anatomy of the vertebrates. 8th edition. Wm. C. Brown Publishers. Dubuque. 487 pages. They are defined by the structure of the vertebrae, having large semi-circular intercentra below the notochord and smaller paired though prominent pleurocentra on each side above and behind, forming anchoring points for the ribs. This form of complex backbone was found in some crossopterygian fish, the Ichthyostegalia, most Temnospondyli and some Reptiliomorpha. Primitive reptiles kept the complex rachitomous vertebrae, but with the pleurocentra being the more dominant. As a phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Most Recent Common Ancestor
In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms. The MRCA of a set of individuals can sometimes be determined by referring to an established pedigree. 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-genetic, mathematical model or computer simulation. In organisms using sexual reproduction, the ''matrilineal MRCA'' and ''patrilineal MRCA'' are the MRCAs of a given population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by both List of U.S. states and territories by area, area (after Alaska) and List of U.S. states and territories by population, population (after California). Texas shares borders with the states of Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the west, and the Mexico, Mexican States of Mexico, states of Chihuahua (state), Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south and southwest; and has a coastline with the Gulf of Mexico to the southeast. Houston is the List of cities in Texas by population, most populous city in Texas and the List of United States cities by population, fourth-largest in the U.S., while San Antonio is the second most pop ... [...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 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'Histoire Naturel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
