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Antarctanax
''Antarctanax'' is a genus of basal archosauriform that during the Triassic lived in Antarctica. The type species is ''Antarctanax shackletoni''. It was a reptile around the size of an iguana. Discovery and naming During a paleontological expedition to the Transantarctic Mountains in 2010 and 2011, a small skeleton was discovered at the Graphite Peak. In 2019, the type species ''Antarctanax shackletoni'' was named and described by Brandon Robert Peecook, Roger Malcolm Harris Smith and Christian Alfred Sidor. The generic name combines a reference to Antarctica — itself derived from Greek ''anti'', "opposite of", and ''arktikos'', "of the Bear" — with a Greek ''anax'', "ruler", a reference to the Archosauria, the "Ruling Reptiles". The specific name honours Ernest Shackleton, the polar explorer who named the Beardmore Glacier which runs along the Graphite Peak. The holotype, UWBM 95531, was found in a layer of the lower Fremouw Formation, which dates to the Early Trias ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fremouw Formation
The Fremouw Formation is a Triassic-age rock formation in the Transantarctic Mountains of Antarctica. It contains the oldest known fossils of tetrapods from Antarctica, including synapsids, reptiles and amphibians. Fossilized trees have also been found. The formation's beds were deposited along the banks of rivers and on floodplains. During the Triassic, the area would have been a riparian forest at 70–75°S latitude. Stratigraphy The Fremouw Formation is mostly Triassic in age, with the oldest rocks dating back to the latest Permian. Much of the formation is quartzose sandstone that was deposited in stream beds. It overlies the Permian Buckley Formation, which consists of coal and ''Glossopteris'' fossils. The formation is informally divided into lower, middle, and upper units. Most fossils are found in the Lower Fremouw Formation. Here, bones are preserved in fine grained siltstones and mudstones, coarse grained channel sandstones, and conglomerates. Paleoenvironment W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christian Sidor
Christian Alfred Sidor is an American vertebrate paleontologist. He is currently a Professor in the Department of Biology, University of Washington in Seattle, as well as Curator of Vertebrate Paleontology and Associate Director for Research and Collections at the Burke Museum of Natural History and Culture. His research focuses on Permian and Triassic tetrapod evolution, especially on therapsids. Academic and professional background Sidor received a B.S. (with honors) in biology from Trinity College in 1994. He went on to pursue his graduate studies at the University of Chicago, completing his M.S. in 1996 and his Ph.D. in 2000 under the supervision of James Hopson. Sidor won the Romer Prize in 2001 for his doctoral work, a competitive annual award at the Society of Vertebrate Paleontology annual meeting for the best predoctoral student oral presentation. Following his dissertation, Sidor held a postdoctoral fellowship at the National Museum of Natural History (2001) before bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosauriformes
Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Latest Permian (roughly 252 million years ago). It was defined by Jacques Gauthier (1994) as the clade stemming from the last common ancestor of Proterosuchidae and Archosauria (the group that contains crocodiles, pterosaurs and dinosaurs bird.html"_;"title="ncluding_bird">ncluding_birds;_Phil_Senter.html" ;"title="bird">ncluding_birds.html" ;"title="bird.html" ;"title="ncluding bird">ncluding birds">bird.html" ;"title="ncluding bird">ncluding birds; Phil Senter">bird">ncluding_birds.html" ;"title="bird.html" ;"title="ncluding bird">ncluding birds">bird.html" ;"title="ncluding bird">ncluding birds; Phil Senter (2005) defined it as the most exclusive clade containing ''Proterosuchus'' and Archosauria. These reptiles, which include members of the Family (biology), family Proterosuchidae and more advanced forms, were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eucrocopoda
Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Latest Permian (roughly 252 million years ago). It was defined by Jacques Gauthier (1994) as the clade stemming from the last common ancestor of Proterosuchidae and Archosauria (the group that contains crocodiles, pterosaurs and dinosaurs bird.html"_;"title="ncluding_bird">ncluding_birds;_Phil_Senter.html" ;"title="bird">ncluding_birds.html" ;"title="bird.html" ;"title="ncluding bird">ncluding birds">bird.html" ;"title="ncluding bird">ncluding birds; Phil Senter">bird">ncluding_birds.html" ;"title="bird.html" ;"title="ncluding bird">ncluding birds">bird.html" ;"title="ncluding bird">ncluding birds; Phil Senter (2005) defined it as the most exclusive clade containing ''Proterosuchus'' and Archosauria. These reptiles, which include members of the family Proterosuchidae and more advanced forms, were originally superficiall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Spine
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank (i.e., location within the backbone), and on the other with phylogenetic differences among the vertebrate taxa. The basic configuration of a vertebra varies, but the bone is its ''body'', with the central part of the body constituting the ''centrum''. The upper (closer to) and lower (further from), respectively, the cranium and its central nervous system surfaces of the vertebra body support attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch (in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lopingian
The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic. The Lopingian is often synonymous with the informal terms late Permian or upper Permian. The name was introduced by Amadeus William Grabau in 1931 and derives from Leping, Jiangxi in China. It consists of two stages/ ages. The earlier is the Wuchiapingian and the later is the Changhsingian. The International Chronostratigraphic Chart (v2018/07) provides a numerical age of 259.1 ±0.5 Ma. If a Global Boundary Stratotype Section and Point (GSSP) has been approved, the lower boundary of the earliest stage determines numerical age of an epoch. The GSSP for the Wuchiapingian has a numerical age of 259.8 ± 0.4 Ma. Evidence from Milankovitch cycles suggests that the length of an Earth day during this epoch was approximately 22 hours. The Lopingian ended with the Permian–Triassic extinction event. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ghost Lineage
A ghost lineage is a hypothesized ancestor in a species lineage that has left no fossil evidence yet can be inferred to exist because of gaps in the fossil record or genomic evidence. The process of determining a ghost lineage relies on fossilized evidence before and after the hypothetical existence of the lineage and extrapolating relationships between organisms based on phylogenetic analysis. Ghost lineages assume unseen diversity in the fossil record and serve as predictions for what the fossil record could eventually yield; these hypotheses can be tested by unearthing new fossils or running phylogenetic analyses. Ghost lineages and Lazarus taxa are related concepts, as both stem from gaps in the fossil record. A ghost lineage is any gap in a taxon's fossil record, with or without reappearance, while a Lazarus taxon is a type of ghost lineage wherein a species is believed to have gone extinct due to an absence in the fossil record, but then reappears after a period of time. Exa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythrosuchidae
Erythrosuchidae (meaning "red crocodiles" in Greek) are a family of large basal archosauriform carnivores that lived from the later Early Triassic (Olenekian) to the early Middle Triassic (Anisian). Naming The family Erythrosuchidae was named by David Meredith Seares Watson in 1917.D.M.S. Watson. 1917. "A sketch classification of the Pre-Jurassic tetrapod vertebrates". ''Proceedings of the Zoological Society of London'' 1917: 167–186 Description They were the apex predators of their day, with lengths of to almost . Their fossil remains are known to date from South Africa (Beaufort Group of the Karoo Basin), China, India and European Russia, from the Early to Middle Triassic. Erythrosuchids were unusually large and robust archosauromorphs. Several features set them apart from other archosauriformes and are also seen in later, more derived archosaurs. For example, they lack teeth on the palate, which are found in other early archosauriformes, such as ''Doswellia'' and eupar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuyosuchus
''Cuyosuchus'' is an extinct genus of archosauriform reptile. Its fossils have been found in Late Triassic-aged rocks of the Cacheuta Formation, Cuyo Basin, Mendoza, Argentina. ''Cuyosuchus'' is based on MCNAM 2669, a partial postcranial skeleton including 26 vertebrae from all parts of the spinal column, ribs, partial pectoral girdles, part of the pelvis, upper arms and part of the lower arms, the left thigh bone and shin, pitted armor scutes, and fragments. It was described in 1961 by Osvaldo Reig and named after the Cuyo Basin; the type species is ''C. huenei'', referring to German paleontologist Friedrich von Huene. Although originally described as a proterosuchid Proterosuchidae is an early family of basal archosauriforms whose fossils are known from the Latest Permian and the Early Triassic of Europe, Asia, Africa, Australia and possibly South America. The name comes from Greek πρότερο- ("first") ..., restudy by Julia Desojo and colleagues in 2003 found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarmatosuchus
''Sarmatosuchus'' is an extinct genus of archosauriform reptile found in sediments of Middle Triassic age and known from the single species ''Sarmatosuchus otschevi''. It is one of the earliest stem-archosaur species known. The holotype and only specimen was found in lithified river deposits of the Donguz Formation exposed near the Berdyanka River, Orenburg region, Russia. 1994 "Pervyj srednetriansovyj proteroscchid iz Vostochnoy Evropy." ''Doklady Akademii Nauk'' 336:359-661 The genus was originally included in the extinct family Proterosuchidae. However, later analysis by David Gower and Andrei Sennikov, the describing author, has removed it from the Proterosuchidae and designated it a basal archosauriform Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Latest Permian (roughly 252 million years ago). It was defined by Jacques Gauthier .... & 1997, "Sarmatosuc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fugusuchus
''Fugusuchus'' is an extinct genus of archosauriform, probably the basal-most member of the family Erythrosuchidae. The genus is known from a single fossil from the middle Early Triassic Heshanggou Formation in Shanxi, China. The partial skeleton consists of an incomplete skull, parts of the right forelimb, and an intercentrum. The skeleton, known as GMB V 313, is currently in the Geological Museum of China in Beijing. ''Fugusuchus'' was a medium-sized archosauriform. It has a long and relatively low skull, unlike the higher more pointed skulls of related genera such as ''Erythrosuchus''. In ''Fugusuchus'', the tooth row of the upper jaw extends beneath the orbit, or eye socket. This feature distinguishes it from more advanced erythrosuchids such as ''Garjainia ''Garjainia'' is an extinct genus of erythrosuchid archosauriform reptile from the Olenekian of Russia and South Africa. It was approximately 1.50–2 m (5–6 ft 8 in) long. It contained two species, ''Garjainia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polytomy
An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tree that contains any multifurcations can be described as a multifurcating tree. Soft polytomies vs. hard polytomies Two types of polytomies are recognised, soft and hard polytomies. Soft polytomies are the result of insufficient phylogenetic information: though the lineages diverged at different times – meaning that some of these lineages are closer relatives than others, and the available data does not allow recognition of this. Most polytomies are soft, meaning that they would be resolved into a typical tree of dichotomies if better data were available. In contrast, a hard polytomy represents a true divergence event of three or more lineages. Applications Interpretations for a polytomy depend on the individuals, that are represe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
