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Dinosauromorphs
Dinosauromorpha is a clade of avemetatarsalians (archosaurs closer to birds than to crocodilians) that includes the Dinosauria (dinosaurs) and some of their close relatives. It was originally defined to include dinosauriforms and lagerpetids, with later formulations specifically excluding pterosaurs from the group. Birds are the only dinosauromorphs which survive to the present day. Classification The name "Dinosauromorpha" was briefly coined by Michael J. Benton in 1985. It was considered an alternative name for the group "Ornithosuchia", which was named by Jacques Gauthier to correspond to archosaurs closer to dinosaurs than to crocodilians. Although "Ornithosuchia" was later recognized as a misnomer (since ornithosuchids are now considered closer to crocodilians than to dinosaurs), it was still a more popular term than Dinosauromorpha in the 1980s. The group encompassed by Gauthier's "Ornithosuchia" and Benton's "Dinosauromorpha" is now given the name Avemetatarsalia. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is divided in chronostratigraphy. The Middle Triassic spans the time between annum, Ma and Ma (million years ago). It is preceded by the Early Triassic Epoch and followed by the Late Triassic Epoch. The Middle Triassic is divided into the Anisian and Ladinian age (geology), ages or stage (stratigraphy), stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of stratum, rock strata with approximately Middle Triassic age, found in western Europe. Middle Triassic life Following the Permian–Triassic extinction event, the most devastating of all mass-extinctions, life recovered slowly. In the Middle Triassic, many groups of organisms reached higher diversity again, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saltopus
''Saltopus'' ("hopping foot") is a genus of very small bipedal dinosauriform containing the single species ''Saltopus elginensis'' from the late Triassic period of Scotland. It is one of the most famous Elgin Reptiles. Description ''Saltopus elginensis'' is known only from a single partial skeleton lacking the skull, but including parts of the vertebral column, the forelimbs, the pelvis and the hindlimbs. These have been mainly preserved as impressions or natural casts in the sandstone; very little bone material is present.Huene, F.R. von (1910). "Ein primitiver Dinosaurier aus der mittleren Trias von Elgin." ''Geol. Pal. Abh. n. s.'', 8: 315-322. It was about the size of a domestic cat, and would have been roughly long. It had hollow bones like those of birds and other dinosaurs. It may have weighed around . In 2016, it was estimated to be 50 cm long, 15 cm high at the hips, and 110 g. Most of the length was accounted for by the tail. It had five-fingered hands, with the fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacques Gauthier
Jacques Armand Gauthier (born June 7, 1948, in New York City) is an American vertebrate paleontologist, comparative morphologist, and systematist, and one of the founders of the use of cladistics in biology. Life and career Gauthier is the son of Edward Paul Gauthier and Patricia Marie Grogan. He received a B.S. degree in zoology at San Diego State University in 1973, a master's in biological science at the same institute in 1980, and a PhD in paleontology from the University of California, Berkeley, in 1984. Currently he is a professor of geology and geophysics and ecology and evolutionary biology and curator of vertebrate paleontology and vertebrate zoology at Yale University. His master's thesis, the content of which was published in 1982, is a classic work on the paleontology and phylogeny of the lizard clade Anguimorpha that remains a core reference for morphological research on Xenosauridae and Anguidae in particular. His PhD thesis constituted the first major cladi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marasuchus Hip Photo
''Marasuchus'' (meaning "Mara crocodile") is a genus of basal dinosauriform archosaur which is possibly synonymous with ''Lagosuchus''. Both genera lived during the Late Triassic in what is now La Rioja Province, Argentina. ''Marasuchus'' contains a single species, ''Marasuchus lilloensis''. ''Marasuchus lilloensis'' was originally designated as ''Lagosuchus lilloensis'' in 1972. It was considered a new species of ''Lagosuchus'', a contemporary archosaur described the previous year. However, a 1994 study argued that the original material of ''Lagosuchus'' was undiagnostic. This would mean that ''Lagosuchus'' and its original species (''Lagosuchus talampayaensis)'' could be considered nomen dubia. Specimens of ''Lagosuchus'' stored at a museum in San Miguel de Tucuman were considered to be more diagnostic than those of ''L. talampayensis'', and thus they were given a new genus: ''Marasuchus''. A 2019 study redescribed the original material of ''Lagosuchus'' and concluded that it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterosaur
Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger. There were two major types of pterosaurs. Basal pterosaurs (also called 'non-pterodactyloid pterosaurs' or ' rhamphorhynchoids') were smaller animals with fully toothed jaws and, typically, long tails. Their wide wing membranes probably included and connected the hind legs. On the ground, they would have had an awkward sprawling posture, but the anatomy of their joints and strong claws would have made them effective climbers, and some may have even lived in trees. Basal pterosaurs were insectivores or predators of small vertebrates. Later pte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagerpetidae
Lagerpetidae (; originally Lagerpetonidae) is a family of basal avemetatarsalians (early-diverging members of the reptile lineage leading to birds and other dinosaurs). Though traditionally considered the earliest-diverging dinosauromorphs (archosaurs closer to dinosaurs than to pterosaurs), fossils described in 2020 suggested that lagerpetids are instead an early branch of pterosauromorphs (closer to pterosaurs than to dinosaurs). Lagerpetid fossils are known from the Triassic of San Juan (Argentina), Arizona, New Mexico, and Texas (United States), Rio Grande do Sul (Brazil), and Madagascar. ''Scleromochlus'', a minuscule archosaur from Scotland, is sometimes regarded as a lagerpetid or close relative of the family. Lagerpetids were generally small and lightly-built animals; the largest include '' Dromomeron gigas'' (from Argentina) and an indeterminate ''Dromomeron'' specimen from the Santa Rosa Formation of Texas, reaching a femoral length of . Lagerpetid fossils are rare ... [...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] |
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] |
Clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy adopted by most biological fields. The common ancestor may be an individual, a population, or a species (extinct or Extant taxon, extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed ''monophyletic'' (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming Taxon, taxa that are not clades; that is, taxa that are not Monophyly, monophyletic. Some of the relationships between organisms that the molecul ... [...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] |
