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Poposauroids
Poposauroidea is a clade of advanced pseudosuchians ( archosaurs closer to crocodilians than to dinosaurs). It includes poposaurids, shuvosaurids, ctenosauriscids, and other unusual pseudosuchians such as ''Qianosuchus'' and '' Lotosaurus''. However, it excludes most large predatory quadrupedal "rauisuchians" such as rauisuchids and "prestosuchids". Those reptiles are now allied with crocodylomorphs (crocodile ancestors) in a clade known as Loricata, which is the sister taxon to the poposauroids in the clade Paracrocodylomorpha. Although it was first formally defined in 2007, the name "Poposauroidea" has been used for many years. The group has been referred to as Poposauridae by some authors, although this name is often used more narrowly to refer to the family that includes ''Poposaurus'' and its close relatives. Poposauroids went extinct at the end of the Triassic period along with other non-crocodylomorph pseudosuchians. However, they were among the most diverse and long-las ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lotosaurus
''Lotosaurus'' is an extinct genus of sail-backed poposauroid known from Hunan Province of central China. Discovery ''Lotosaurus'' is known from the holotype IVPP V 4881 (or possibly V 4880), an articulated and well-preserved skeleton. Other referred specimens include IVPP V 48013 (a skull) as well as many articulated and disarticulated skeletal remains concentrated in a bonebed which is almost completely composed of ''Lotosaurus'' bones. All known specimens of this genus were collected from this bonebed, known as the ''Lotosaurus'' site, which belongs to the Batung Formation (or alternatively Xinlingzhen Formation of the Badong Group). Further excavations in 2018 revealed many more specimens, as well as geological and environmental details of the ''Lotosaurus'' site. At least 38 individuals of various ages died within this one location. ''Lotosaurus'' was first named by Fa-kui Zhang in 1975 and the type species is ''Lotosaurus adentus''. ''Lotosauru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effigia
''Effigia'' was an Extinction, extinct genus of Shuvosauridae, shuvosaurid known from the Late Triassic of New Mexico, south-western USA. With a bipedal stance, long neck, and a toothless beaked skull, ''Effigia'' and other shuvosaurids bore a resemblance to the ornithomimidae, ornithomimid Dinosaur, dinosaurs of the Cretaceous, Cretaceous Period. However, shuvosaurids were not dinosaurs, but were instead a specialized family of Poposauroidea, poposauroid Pseudosuchia, pseudosuchians, meaning that their closest living relatives are crocodilians. Discovery The 2-meter (6 ft 7 in) holotype fossil was collected by Edwin H. Colbert in 1947. At this time Colbert led an excavation to collect blocks of rock from the Whitaker Quarry of Ghost Ranch, near Abiquiú, New Mexico, Abiquiu, New Mexico. Colbert's expedition intended to recover abundant fossils of the Basal (phylogenetics), basal Theropoda, theropod dinosaur ''Coelophysis'', and he believed that no other large Vertebrate, vertebr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poposaurus
''Poposaurus'' (" Popo Agie reptile") is an extinct genus of pseudosuchian archosaur from the Late Triassic of the southwestern United States. It belongs to the clade Poposauroidea, an unusual group of Triassic pseudosuchians that includes sail-backed, beaked, and aquatic forms. Fossils have been found in Wyoming, Utah, Arizona, and Texas. Except for the skull, most parts of the skeleton are known. The type species, ''P. gracilis'', was described and named by Maurice Goldsmith Mehl in 1915. A second species, ''P. langstoni'', was originally the type species of the genus ''Lythrosuchus''. Since it was first described, ''Poposaurus'' has been variously classified as a dinosaur, a phytosaur, and a " rauisuchian". Like theropod dinosaurs, ''Poposaurus'' was an obligate biped, meaning that it walked on two legs rather than four. However, as a pseudosuchian, it is more closely related to living crocodilians than to dinosaurs. ''Poposaurus'' is thought to have evolved this form of lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qianosuchus
''Qianosuchus'' is an extinct genus of aquatic poposauroid archosaur from the middle Triassic (Anisian) Guanling Formation of Pan County, China. It is represented by two nearly complete skeletons and a crushed skull preserved in the limestone. ''Qianosuchus'' was at least 3 metres long, and had several skeletal adaptations which indicate a semi-marine lifestyle, similar to modern-day saltwater crocodiles. These adaptations have not been seen in any other archosaur from the Triassic. Description ''Qianosuchus'' had a skull around 33 cm (13 inches) long, with an elongated snout. The rostrum formed by the premaxilla is shallow at the front of the skull but deepens posteriorly. Each premaxilla has nine long teeth, and the maxillae bear eighteen teeth each. All the teeth are laterally compressed, curved backwards and serrated, like those of most other carnivorous archosaurs. The nares are expanded and elongated and almost collide with the antorbital fenestrae, meaning that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poposauridae
Poposauridae is a family of large carnivorous archosaurs which lived alongside dinosaurs during the Late Triassic. They were around long. Poposaurids are known from fossil remains from North and South America. While originally believed to be theropod dinosaurs (they mirrored the theropods in a number of respects, such as features of the skull and bipedal locomotion), cladistic analysis has shown them to be more closely related to crocodiles. An early cladistic analysis of crocodylotarsan archosaurs included ''Poposaurus'', ''Postosuchus'', ''Teratosaurus'', and ''Bromsgroveia'' within Poposauridae.Parrish JM. 1993. Phylogeny of the Crocodylotarsi, with reference to archosaurian and crurotarsan monophyly. ''Journal of Vertebrate Paleontology'' 13: 287-308. However, later studies found ''Teratosaurus'' to be a rauisuchid.Long RA, Murry PA. 1995. Late Triassic (Carnian and Norian) tetrapods from the Southwestern United States. ''New Mexico Museum of Natural History & Science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shuvosauridae
Shuvosauridae is an extinct family of theropod-like pseudosuchians within the clade Poposauroidea. Shuvosaurids existed in North America (United States) and South America (Argentina) during the Late Triassic period (late Carnian to Rhaetian stages). Shuvosauridae was named by Sankar Chatterjee in 1993 to include the genus ''Shuvosaurus''. In a 2007 study ''Chatterjeea'' was demonstrated to be a junior synonym of ''Shuvosaurus'', and the therein cladistic analysis found that ''Shuvosaurus'', ''Effigia'' and '' Sillosuchus'' all form a closely related group. However, this group was left nameless, and simply referred to as Group Y. However, in accordance with ICZN rules of naming priority Shuvosauridae has priority over Chatterjeeidae (Shuvosauridae being named in 1993, while Chatterjeeidae was named in 1995). In 2011, Sterling J. Nesbitt proposed a new definition to this clade: "The least inclusive clade containing ''Shuvosaurus ''Shuvosaurus'' (meaning "Shuvo's lizard") is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shuvosaurinae
Shuvosauridae is an extinct family of theropod-like pseudosuchians within the clade Poposauroidea. Shuvosaurids existed in North America (United States) and South America (Argentina) during the Late Triassic period (late Carnian to Rhaetian stages). Shuvosauridae was named by Sankar Chatterjee in 1993 to include the genus ''Shuvosaurus''. In a 2007 study ''Chatterjeea'' was demonstrated to be a junior synonym of ''Shuvosaurus'', and the therein cladistic analysis found that ''Shuvosaurus'', ''Effigia'' and '' Sillosuchus'' all form a closely related group. However, this group was left nameless, and simply referred to as Group Y. However, in accordance with ICZN rules of naming priority Shuvosauridae has priority over Chatterjeeidae (Shuvosauridae being named in 1993, while Chatterjeeidae was named in 1995). In 2011, Sterling J. Nesbitt proposed a new definition to this clade: "The least inclusive clade containing ''Shuvosaurus ''Shuvosaurus'' (meaning "Shuvo's lizard") is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poposaurid
Poposauridae is a family of large carnivorous archosaurs which lived alongside dinosaurs during the Late Triassic. They were around long. Poposaurids are known from fossil remains from North and South America. While originally believed to be theropod dinosaurs (they mirrored the theropods in a number of respects, such as features of the skull and bipedal locomotion), cladistic analysis has shown them to be more closely related to crocodiles. An early cladistic analysis of crocodylotarsan archosaurs included ''Poposaurus'', '' Postosuchus'', '' Teratosaurus'', and '' Bromsgroveia'' within Poposauridae.Parrish JM. 1993. Phylogeny of the Crocodylotarsi, with reference to archosaurian and crurotarsan monophyly. ''Journal of Vertebrate Paleontology'' 13: 287-308. However, later studies found '' Teratosaurus'' to be a rauisuchid.Long RA, Murry PA. 1995. Late Triassic (Carnian and Norian) tetrapods from the Southwestern United States. ''New Mexico Museum of Natural History & Scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Triassic
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a unit in chronostratigraphy. The Early Triassic is the oldest epoch of the Mesozoic Era. It is preceded by the Lopingian Epoch (late Permian, Paleozoic Era) and followed by the Middle Triassic Epoch. The Early Triassic is divided into the Induan and Olenekian ages. The Induan is subdivided into the Griesbachian and Dienerian subages and the Olenekian is subdivided into the Smithian and Spathian subages. The Lower Triassic series is coeval with the Scythian Stage, which is today not included in the official timescales but can be found in older literature. In Europe, most of the Lower Triassic is composed of Buntsandstein, a lithostratigraphic unit of continental red beds. The Early Triassic and partly also the Middle Triassic s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paracrocodylomorpha
Paracrocodylomorpha is a clade of pseudosuchian archosaurs. The clade includes the diverse and unusual group Poposauroidea as well as the generally carnivorous and quadrupedal members of Loricata, including modern crocodylians. Paracrocodylomorpha was named by paleontologist J. Michael Parrish in 1993, although the group is now considered to encompass more reptiles than his original definition intended. The most recent definition of Paracrocodylomorpha, as defined by Sterling Nesbitt in 2011, is "the least inclusive clade containing ''Poposaurus'' and ''Crocodylus niloticus'' (the Nile crocodile). Most groups of paracrocodylomorphs became extinct at the end of the Triassic period, with the exception of the crocodylomorphs, from which crocodylians such as crocodiles and alligators evolved in the latter part of the Mesozoic. History and definition Parrish (1993) defined Paracrocodylomorpha as the last common ancestor of " Poposauridae" and Crocodylomorpha and all of its descend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic, Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas '' homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to para ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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