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Rhadinosuchidae
Proterochampsidae is a family of proterochampsian archosauriforms. Proterochampsids may have filled an ecological niche similar to modern crocodiles, and had a general crocodile-like appearance. They lived in what is now South America in the Middle and Late Triassic. Description Proterochampsids have long, crocodile-like skulls. The posterior portion of the skull is wide while the snout is very narrow. Most proterochampsids also have downturned snouts. Like many early archosauriforms, they also have dermal armour. Proterochampsids have small holes called dorsal fenestrae at the top of their skulls. Unlike other early archosauromorphs, they do not have a parietal foramin, which in many reptiles holds a parietal eye. The postorbital bones behind the eye sockets have thick, jagged crests. As another diagnostic feature of the group, the holes that allow the passage of the internal carotid artery through the braincase open at the sides of a bony projection called the basipterygoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterochampsia
Proterochampsia is a clade of early archosauriform reptiles from the Triassic period. It includes the Proterochampsidae (e.g. '' Proterochampsa'', '' Chanaresuchus'' and '' Tropidosuchus'') and probably also the Doswelliidae. Nesbitt (2011) defines Proterochampsia as a stem-based taxon that includes '' Proterochampsa'' and all forms more closely related to it than ''Euparkeria'', ''Erythrosuchus'', ''Passer domesticus'' (the House Sparrow), or ''Crocodylus niloticus'' (the Nile crocodile). Therefore, the inclusion of Doswelliidae in it is dependent upon whether ''Doswellia'' and '' Proterochampsa'' form a monophyletic group to the exclusion of Archosauria and other related groups. Description Nesbitt (2011) found that Proterochampsians share several distinguishing characteristics, or synapomorphies. A prominent ridge runs along the length of the jugal, a bone below the eye. Another ridge is present on the quadratojugal, a bone positioned toward the back of the skull behind the j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chanaresuchus
''Chanaresuchus'' is an extinct genus of proterochampsian archosauriform. It was of modest size for a proterochampsian, being on average just over a meter in length. Fossils are known from the Middle and Late Triassic of La Rioja Province, Argentina and Rio Grande do Sul (geoparque Paleorrota), Brazil. The type species and only currently known species is ''Chanaresuchus bonapartei'' was named from the Ladinian-age Chañares Formation in 1971. A second species ''C. ischigualastensis'' named in 2012 from the late Carnian-age Ischigualasto Formation, was briefly assigned to ''Chanaresuchus'' before being moved to its own genus '' Pseudochampsa'' in 2014. ''C. bonapartei'' has recently been found in the Carnian Santa Maria Formation in Brazil. ''Chanaresuchus'' appears to be one of the most common archosauriforms from the Chanares Formation due to the abundance of specimens referred to the genus. Much of the material has been found by the La Plata-Harvard expedition of 1964-65. ''Cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between 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 ages or stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of rock strata with approximately Middle Triassic age, found in western Europe. Middle Triassic fauna 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, such as the marine reptiles (e.g. ichthyosaurs, sauropterygians, thallatosaurs), ray-finned fish and many invertebrate groups like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parietal Eye
A parietal eye, also known as a third eye or pineal eye, is a part of the epithalamus present in some vertebrates. The eye is located at the top of the head, is photoreceptive and is associated with the pineal gland, regulating circadian rhythmicity and hormone production for thermoregulation. The hole in the head which contains the eye is known as a pineal foramen or parietal foramen, since it is often enclosed by the parietal bones. Presence in various animals The parietal eye is found in the tuatara, most lizards, frogs, salamanders, certain bony fish, sharks, and lampreys. It is absent in mammals, but was present in their closest extinct relatives, the therapsids, suggesting it was lost during the course of the mammalian evolution due to it being useless in endothermic animals. It is also absent in the ancestrally endothermic ("warm-blooded") archosaurs such as birds. The parietal eye is also lost in ectothermic ("cold-blooded") archosaurs like crocodilians, and in turtles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Taxon
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomi ... [...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 originated pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proterosuchia
Proterosuchia is one of the suborders of the paraphyletic group Thecodontia; containing the most primitive and ancestral forms. These were primitive, vaguely crocodile-like, archosauriforms that mostly lived during the Early Triassic epoch. The name Proterosuchia was coined by Robert Broom in 1906. In later classifications, several families were included, such as Proterosuchidae, Erythrosuchidae, and Proterochampsidae. Under the cladistic system, this is a paraphyletic grade, rather than a natural group. The name is therefore no longer used, although it can be found in many textbooks (up to and including Carroll's ''Vertebrate Paleontology and Evolution'') In current phylogenetic understanding, the Proterosuchia constitute the basal 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Romer
Alfred Sherwood Romer (December 28, 1894 – November 5, 1973) was an American paleontologist and biologist and a specialist in vertebrate evolution. Biography Alfred Romer was born in White Plains, New York, the son of Harry Houston Romer and his wife, Evalyn Sherwood. He was educated at White Plains High School. He studied at Amherst College for his Bachelor of Science Honours degree in biology, then at Columbia University for an M.Sc in Biology and a doctorate in zoology in 1921. Romer joined the department of geology and paleontology at the University of Chicago as an associate professor in 1923. He was an active researcher and teacher. His collecting program added important Paleozoic specimens to Chicago's Walker Museum of Paleontology. In 1934 he was appointed professor of biology at Harvard University. In 1946, he became director of the Harvard Museum of Comparative Zoology (MCZ). In 1954 Romer was awarded the Mary Clark Thompson Medal from the National Academy of Sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibia
The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects the knee with the ankle. The tibia is found on the medial side of the leg next to the fibula and closer to the median plane. The tibia is connected to the fibula by the interosseous membrane of leg, forming a type of fibrous joint called a syndesmosis with very little movement. The tibia is named for the flute ''tibia''. It is the second largest bone in the human body, after the femur. The leg bones are the strongest long bones as they support the rest of the body. Structure In human anatomy, the tibia is the second largest bone next to the femur. As in other vertebrates the tibia is one of two bones in the lower leg, the other being the fibula, and is a component of the knee and ankle joints. The ossification or formation of the bone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astragalus
''Astragalus'' is a large genus of over 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species. The genus is native to temperate regions of the Northern Hemisphere. Common names include milkvetch (most species), locoweed (in North America, some species) and goat's-thorn ( ''A. gummifer'', ''A. tragacantha''). Some pale-flowered vetches (''Vicia'' spp.) are similar in appearance, but they are more vine-like than ''Astragalus''. Description Most species in the genus have pinnately compound leaves. There are annual and perennial species. The flowers are formed in clusters in a raceme, each flower typical of the legume family, with three types of petals: banner, wings, and keel. The calyx is tubular or bell-shaped. Ecology ''Astragalus'' species are used as food plants by the larvae of some Lepidoptera species including many case-bearing moths of the genus ''Col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tarsus (skeleton)
In the human body, the tarsus is a cluster of seven articulating bones in each foot situated between the lower end of the tibia and the fibula of the lower leg and the metatarsus. It is made up of the midfoot (Cuboid bone, cuboid, medial, intermediate, and lateral cuneiform bone, cuneiform, and navicular) and hindfoot (Talus bone, talus and calcaneus). The tarsus articulates with the bones of the metatarsus, which in turn articulate with the proximal phalanges of the toes. The joint between the tibia and fibula above and the tarsus below is referred to as the ankle, ankle joint proper. In humans the largest bone in the tarsus is the calcaneus, which is the weight-bearing bone within the heel of the foot. Human anatomy Bones The talus bone or ankle bone is connected superiorly to the two bones of the lower leg, the tibia and fibula, to form the ankle, ankle joint or talocrural joint; inferiorly, at the subtalar joint, to the calcaneus or heel bone. Together, the talus and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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