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Crurotarsal
A crurotarsal joint is one that's situated between the bones of '' crus'', i.e. shin (tibia and fibula) and the proximal tarsal bones, i.e. astragalus and calcaneum. The ankle joint of therian mammals ( marsupials and placentals) is a crurotarsal joint, with the main joint of ankle bending between the tibia and the astragalus; the calcaneum has no contact with the tibia but forms a heel to which muscles can attach. A group of archosauriform diapsids, Crurotarsi (including living crocodilians and their extinct relatives) is named after specialized crurotarsal joint in the skeletons of the members of this group, located between their fibula and calcaneum, with a hemicylindrical condyle on the calcaneum articulating against fibula. This joint is present in the skeletons of suchians (including crocodilians) and phytosaurs, and was cited as one of the characters supporting uniting these two groups in a clade to the exclusion of avemetatarsalian archosaurs (birds and their extinct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosaur
Archosauria () or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only extant taxon, extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistics, cladistic sense of the term includes all living and extinct relatives of birds and crocodilians such as non-avian dinosaurs, pterosaurs, phytosaurs, aetosaurs and rauisuchians as well as many marine reptile#Extinct groups, Mesozoic marine reptiles. 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 morphology (biology), morphological ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crurotarsi
Crurotarsi is a clade of archosauriform reptiles that includes crocodilians and stem-crocodilians and possibly bird-line archosaurs too if the extinct, crocodile-like phytosaurs are more distantly related to crocodiles than traditionally thought. Prior to 2011, the group had invariably included only archosaurs closer to crocodilians than to birds and other dinosaurs. An equivalent term for the crocodilian side of the archosaur family tree is Pseudosuchia. This traditional definition of Crurotarsi assumed that phytosaurs were crown-group archosaurs and more closely related to crocodilians than to birds. However, a 2011 study argued that the phytosaur lineage evolved prior to the split between birds and crocodilians. This would mean that phytosaurs were not true archosaurs, and therefore could not be considered representatives of croc-line archosaurs. The name Crurotarsi is derived from the Latin word '' crus'' (lower leg) and the Greek word '' tarsos'' (ankle). It refers to the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suture (anatomical)
In anatomy, a suture is a fairly rigid joint between two or more hard elements of an organism, with or without significant overlap of the elements. Sutures are found in the skeletons or exoskeletons of a wide range of animals, in both invertebrates and vertebrates. Sutures are found in animals with hard parts from the Cambrian period to the present day. Sutures were and are formed by several different methods, and they exist between hard parts that are made from several different materials. Vertebrate skeletons The skeletons of vertebrate animals (fish, amphibians, reptiles, birds, and mammals) are made of bone, in which the main rigid ingredient is calcium phosphate. Cranial sutures The skulls of most vertebrates consist of sets of bony plates held together by cranial sutures. These sutures are held together mainly by Sharpey's fibers which grow from each bone into the adjoining one. Sutures in the ankles of land vertebrates In the type of crurotarsal ankle, which is found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytosaur
Phytosaurs (Φυτόσαυροι in Greek, meaning 'plant lizard') are an extinct group of large, mostly semiaquatic Late Triassic archosauriform or basal archosaurian reptiles. Phytosaurs belong to the order Phytosauria and are sometimes referred to as parasuchians. Phytosauria, Parasuchia, Parasuchidae, and Phytosauridae have often been considered equivalent groupings containing the same species. Some recent studies have offered a more nuanced approach, defining Parasuchidae and Phytosauridae as nested clades within Phytosauria as a whole. The clade Phytosauria was defined by Paul Sereno in 2005 as '' Rutiodon carolinensis'' and all taxa more closely related to it than to '' Aetosaurus ferratus'', '' Rauisuchus tiradentes'', '' Prestosuchus chiniquensis'', '' Ornithosuchus woodwardi'', or '' Crocodylus niloticus'' (the Nile crocodile). Phytosaurs were long-snouted and heavily armoured, bearing a remarkable resemblance to modern crocodilians in size, appearance, and lifesty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suchia
Suchia (from Ancient Greek σούχος (''soúkhos''), meaning "crocodile") is a clade of archosaurs containing the majority of pseudosuchians (crocodilians and their extinct relatives). It was defined as the least inclusive clade containing ''Aetosaurus, Aetosaurus ferratus'', ''Rauisuchus, Rauisuchus tiradentes'', ''Prestosuchus, Prestosuchus chiniquensis'', and ''Crocodylus niloticus'' (the living Nile crocodile) by Nesbitt (2011). Generally the only pseudosuchian group which is omitted from Suchia is the Family (biology), family Ornithosuchidae, although at least one analysis classifies ornithosuchids as close relatives of Erpetosuchidae, erpetosuchids (which are usually considered suchians) and aetosaurs (which are suchians by definition of the group). Phytosaurs are also excluded from Suchia, although it is not certain whether they qualify as pseudosuchians in the first place. There is some controversy over which traits, if any, can be used to distinguish suchians from non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosauriformes
Archosauriformes (Ancient Greek, Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles encompassing Archosaur, archosaurs and some of their close relatives. It was defined by Jacques Gauthier (1994) as the clade stemming from the Most recent common ancestor, last common ancestor of Proterosuchidae and Archosauria. Phil Senter (2005) defined it as the most exclusive clade containing ''Proterosuchus'' and Archosauria. Gauthier as part of the ''Phylonyms'' (2020) defined the clade as the last common ancestor of ''Chicken, Gallus'', ''Alligator'', and ''Proterosuchus'', and all its descendants. Archosauriforms are a branch of Archosauromorpha, archosauromorphs which originated in the Late Permian (roughly 252 million years ago) and persist to the present day as the two surviving archosaur groups: Crocodilia, crocodilians and Bird, birds. Archosauriforms present several traits historically ascribed to the group Archosauria. These include serrated teeth set in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodilia
Crocodilia () is an order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchian, a subset of archosaurs that appeared about 235 million years ago and were the only survivors of the Triassic–Jurassic extinction event. While other crocodylomorph groups further survived the Cretaceous–Paleogene extinction event, notably sebecosuchians, only the crocodilians have survived into the Quaternary. The order includes the true crocodiles (family Crocodylidae), the alligators and caimans (family Alligatoridae), and the gharial and false gharial (family Gavialidae). Although the term "crocodiles" is sometimes used to refer to all of these families, the term "crocodilians" is less ambiguous. Extant crocodilians have flat heads with long snouts and tails that are compressed on the sides, with their eyes, ears, and n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithosuchidae
Ornithosuchidae is an extinct family (biology), family of Pseudosuchia, pseudosuchian archosaurs (distant relatives of modern Crocodilia, crocodilians) from the Triassic period. Ornithosuchids were quadrupedal and facultatively bipedal (e.g. like Chimpanzee, chimpanzees), meaning that they had the ability to walk on two legs for short periods of time. They had distinctive, downturned snouts, unique, "crocodile-reversed" ankle bones, and several other features that distinguish them from other archosaurs. Ornithosuchids were geographically widespread during the Carnian and Norian stages of the Late Triassic with members known from Argentina, Brazil, and the United Kingdom. Four genera, comprising ''Ornithosuchus'', ''Venaticosuchus, Dynamosuchus,'' and ''Riojasuchus'' are presently known. The family was first erected by German paleontologist Friedrich von Huene in 1908. Description Skull Ornithosuchids can be identified by the presence of an arched Diastema (dentistry), diastem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudosuchia
Pseudosuchia, from Ancient Greek ψεύδος (''pseúdos)'', meaning "false", and σούχος (''soúkhos''), meaning "crocodile" is one of two major divisions of Archosauria, including living crocodilians and all archosaurs more closely related to crocodilians than to birds. Pseudosuchians are also informally known as "crocodilian-line archosaurs", in contrast to the "bird-line archosaurs" or Avemetatarsalia. Despite Pseudosuchia meaning "false crocodiles", the name is a misnomer as true crocodilians are now defined as a subset of the group. The clade Pseudosuchia is potentially equivalent to another term, Crurotarsi, even though the latter has a different, Node-based taxon, node-based definition: "all taxa the least inclusive clade containing ''Rutiodon carolinensis'' (Emmons, 1856), and ''Crocodylus niloticus'' (Laurenti, 1768)." Many paleontologists of the late 20th century took this proposal for granted, using Crurotarsi as the term for crocodilian ancestors. In 2011, a m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a four-chambered heart, and a strong yet lightweight Bird skeleton, skeleton. Birds live worldwide and range in size from the bee hummingbird to the common ostrich. There are over 11,000 living species and they are split into 44 Order (biology), orders. More than half are passerine or "perching" birds. Birds have Bird wing, wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the Flightless bird, loss of flight in some birds, including ratites, penguins, and diverse endemism, endemic island species. The digestive and respiratory systems of birds are also uniquely a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avemetatarsalia
Avemetatarsalia (meaning "bird metatarsals") is a clade of diapsid Reptile, reptiles containing all archosaurs more closely related to birds than to crocodilians. The two most successful groups of avemetatarsalians were the dinosaurs and pterosaurs. Dinosaur, Dinosaurs were the largest terrestrial animals for much of the Mesozoic era, Mesozoic Era, and one group of small feathered dinosaurs (Aves, i.e. birds) has survived up to the present day. Pterosaur, Pterosaurs were the first flying vertebrates and persisted through the Mesozoic before dying out at the Cretaceous–Paleogene extinction event, Cretaceous-Paleogene (K-Pg) extinction event. Both dinosaurs and pterosaurs appeared in the Triassic period, Triassic Period, shortly after avemetatarsalians as a whole. The name Avemetatarsalia was first established by British palaeontologist Michael J. Benton, Michael Benton in 1999. An alternate name is Pan-Aves, or "all birds", in reference to its definition containing all animals, li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
