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Rauisuchian
"Rauisuchia" is a paraphyletic group of mostly large and carnivorous Triassic archosaurs. Rauisuchians are a category of archosaurs within a larger group called Pseudosuchia, which encompasses all archosaurs more closely related to crocodilians than to birds and other dinosaurs. First named in the 1940s, Rauisuchia was a name exclusive to Triassic archosaurs which were generally large (often ), carnivorous, and quadrupedal with a pillar-erect hip posture, though exceptions exist for all of these traits. Rauisuchians, as a traditional taxonomic group, were considered distinct from other Triassic archosaur groups such as early dinosaurs, phytosaurs (crocodile-like carnivores), aetosaurs (armored herbivores), and crocodylomorphs (lightly-built crocodilian ancestors). However, more recent studies on archosaur evolution have upended this idea based on phylogenetic analyses and cladistics, a modern approach to taxonomy based on clades (nested monophyletic groups of common ancestry ... [...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] |
Loricata
Loricata is a clade of archosaur reptiles that includes crocodilians and some of their Triassic relatives, such as '' Postosuchus'' and ''Prestosuchus''. More specifically, Loricata includes Crocodylomorpha (the persistent archosaur subset which crocodilians belong to) and most "rauisuchians", a paraphyletic grade of large terrestrial pseudosuchians which were alive in the Triassic period and ancestral to crocodylomorphs. Loricata is one branch of the group Paracrocodylomorpha; the other branch is the clade Poposauroidea, an unusual collection of strange "rauisuchians" including bipedal, herbivorous, and sail-backed forms. The vast majority of typical "rauisuchians", which were usually quadrupedal predators, occupy basal (early-branching) rungs of Loricata leading up to crocodylomorphs. History and Classification Loricata was initially named in a completely different context by German naturalist Blasius Merrem in his 1820 ''Versuch eines Systems der Amphibien''. Merrem co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saurosuchus
''Saurosuchus'' (meaning "lizard crocodile") is an extinct genus of large loricatan pseudosuchian archosaur that lived in South America during the Late Triassic period. It was a heavy, ground-dwelling, quadrupedal carnivore, likely being the apex predator in the Ischigualasto Formation. Discovery and naming The holotype, PVL 206, was discovered by Galileo J. Scaglia and Leocadio Soria in 1957, lying in a greenish sandstone on the Cancha de Bochas Member of the Ischigualasto Formation in the Ischigualasto-Villa Unión Basin in northwestern Argentina. It consists of a nearly complete, but deformed skull. ''Saurosuchus'' was formally described and named later in 1959 by Osvaldo. A. Reig. The generic name, ''Saurosuchus'', is derived from the Greek (, meaning lizard) and (, meaning crocodile). The specific name, ''galilei'', is in honour to Galileo J. Scaglia, who unearthed and prepared the holotype. Referred specimens ''Saurosuchus'' is known from numerous specimens coming f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aetosaur
Aetosaurs () are heavily armored reptiles belonging to the extinct order (biology), order Aetosauria (; from Ancient Greek, Greek, (aetos, "eagle") and (, "lizard")). They were medium- to large-sized Omnivore, omnivorous or Herbivore, herbivorous Pseudosuchia, pseudosuchians, part of the branch of archosaurs more closely related to crocodilians than to birds and other dinosaurs. All known aetosaurs are restricted to the Late Triassic, and in some strata from this time they are among the most abundant fossil vertebrates. They have small heads, upturned snouts, erect limbs, and a body ornamented with four rows of plate-like Osteoderm, osteoderms (bony scutes). Aetosaur fossil remains are known from Europe, North America, North and South America, parts of Africa, and India. Since their armoured plates are often preserved and are abundant in certain localities, aetosaurs serve as important Late Triassic tetrapod index fossils. Many aetosaurs had wide geographic ranges, but their stra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species, ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poposauroidea
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-l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prestosuchidae
Prestosuchidae (in its widest usage) is a polyphyletic grouping of carnivorous archosaurs that lived during the Triassic. They were large active terrestrial apex predators, ranging from around in length. They succeeded the Erythrosuchidae as the largest archosaurs of their time. While resembling erythrosuchids in size and some features of the skull and skeleton, they were more advanced in their erect posture and crocodile-like ankle, indicating more efficient gait. "Prestosuchids" flourished throughout the whole of the middle, and the early part of the late Triassic, and fossils are so far known from Europe, India, Africa (Tanzania), Argentina, and Paleorrota in Brazil. However, for a long time experts disagree regarding the phylogenetic relationships of the group, what genera should be included, and whether indeed the "Prestosuchidae" constitute a distinct family. In 2011, Prestosuchidae in its broadest definition was determined to be a poorly-diagnosed and obsolete polyphylet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postosuchus
''Postosuchus'', meaning "Crocodile from Post", is an extinct genus of rauisuchid reptiles comprising two species, ''P. kirkpatricki'' and ''P. alisonae'', that lived in what is now North America during the Late Triassic. ''Postosuchus'' is a member of the clade Pseudosuchia, the lineage of archosaurs that includes modern crocodilians (the other main group of archosaurs is Avemetatarsalia, the lineage that includes non-avian dinosaurs and their descendants, birds). Its name refers to Post Quarry, a place in Texas where many fossils of the type species, ''P. kirkpatricki'', were found. It was one of the apex predators of its area during the Triassic, larger than the small dinosaur predators of its time (such as ''Coelophysis''). It was a hunter which probably preyed on large bulky herbivores like dicynodonts and many other creatures smaller than itself (such as early dinosaurs). The skeleton of ''Postosuchus'' is large and robust with a deep skull and a long tail. It was a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
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 Mya. The Jurassic constitutes the middle period of the Mesozoic Era 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. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rauisuchidae
Rauisuchidae is a group of large (up to or more) predatory Triassic archosaurs. There is some disagreement over which genera should be included in Rauisuchidae and which should be in the related Prestosuchidae and Poposauridae, and indeed whether these should even be thought of as separate valid families. Rauisuchids occurred throughout much of the Triassic, and may have first occurred in the Early Triassic if some archosaurian taxa such as ''Scythosuchus'' and ''Tsylmosuchus'' are considered to be within the family. An early cladistic analysis of crocodylotarsan (pseudosuchian) archosaurs included '' Lotosaurus'', ''Fasolasuchus'', ''Rauisuchus'', and "the Kupferzell rauisuchid" (later called ''Batrachotomus'') within Rauisuchidae.Parrish JM. 1993. Phylogeny of the Crocodylotarsi, with reference to archosaurian and crurotarsan monophyly. ''Journal of Vertebrate Paleontology'' 13: 287-308. However, a later study found that ''Batrachotomus'' was a more basal pseudosuchian only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosaur
Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avian dinosaurs, pterosaurs, and extinct relatives of crocodilians. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives, and Avemetatarsalia, which includes birds and their extinct relatives (such as non-avian dinosaurs and pterosaurs). Older definitions of the group Archosauria rely on shared morphological characteristics, such as an antorbital fenestra in the skull, serrated teeth, and an upright stance. Some extinct reptiles, such as proterosuchids and euparkeriids, possessed these features yet originate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wastebasket Taxon
Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined by either their designated members' often superficial similarity to each other, or their ''lack'' of one or more distinct character states or by their ''not'' belonging to one or more other taxa. Wastebasket taxa are by definition either paraphyletic or polyphyletic, and are therefore not considered valid taxa under strict cladistic rules of taxonomy. The name of a wastebasket taxon may in some cases be retained as the designation of an evolutionary grade, however. The term was coined in a 1985 essay by Steven Jay Gould. Examples There are many examples of paraphyletic groups, but true "wastebasket" taxa are those that are known not to, and perhaps not intended to, represent natural groups, but are nevertheless used as convenient gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
