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Dyrosaurids
Dyrosauridae is a family (biology), family of extinct neosuchian crocodyliforms that lived from the Campanian to the Eocene. Dyrosaurid fossils are globally distributed, having been found in Africa, Asia, Europe, North America and South America. Over a dozen species are currently known, varying greatly in overall size and cranial shape. A majority were aquatic, some terrestrial and others fully marine (see locomotion below), with species inhabiting both freshwater and marine environments. Ocean-dwelling dyrosaurids were among the few marine reptiles to survive the Cretaceous–Paleogene extinction event. The dyrosaurids were a group of mostly marine, long jawed, crocodile-like quadrupeds up to long. The largest dyrosaurid was probably ''Phosphatosaurus'' estimated at in length. Based on bone tissue evidence, it has been hypothesized that they were slow-growing near-shore marine animals with interlocking closed jaws, able to swim as well as walk on land. External nostrils at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyposaurus
''Hyposaurus'' is a genus of extinct marine Dyrosauridae, dyrosaurid crocodyliform. Fossils have been found in Paleocene aged rocks of the Iullemmeden Basin in West Africa, Campanian–Maastrichtian (Late Cretaceous, Late Cretaceous) Shendi Formation of Sudan and Maastrichtian (Late Cretaceous) through Danian (Early Paleocene) strata in New Jersey, Alabama and South Carolina. With an Indeterminate species from the Selandian, Mid to Thanetian, Late Paleocene, Palaeocene Teberemt Formation of Mali. Isolated teeth comparable to ''Hyposaurus'' have also been found in Thanetian (Late Paleocene) strata of Virginia.Denton Jr., R. K., Dobie, J. L. and D. C. Parris, 1997. The Marine Crocodilian ''Hyposaurus'' in North America. from Ancient Marine Reptiles, editors J. M. Callaway and E. L. Nicholls, Academic Press. It was related to ''Dyrosaurus''. The priority of the species ''H. rogersii'' has been debated,Norell, M. A. and G. W. Storrs. 1989. Catalogue and review of the type fossil crocod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrops near the village of Aubeterre-sur-Dronne in the same region. Definition The base of the Campanian Stage is defined as a place in the stratigraphic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyrosaurus
''Dyrosaurus'' is a genus of extinct crocodylomorph that lived during the early Eocene. The name ''Dyrosaurus'' comes from () the Greek for lizard or reptile, and Dyr for Djebel Dyr (mountain) close to where the type species was discovered. It was a large reptile with an estimated body length of . Species Although the family Dyrosauridae is quite diverse and contains a variety of species, the genus ''Dyrosaurus'' has only two described species: ''D. phosphaticus'' and ''D. maghribensis''. ''D. phosphaticus'' was first discovered in Algeria and Tunisia whereas ''D. maghribensis'' has only been found in Morocco. ''D. maghribensis'' differs from ''D. phosphaticus'' by several synapomorphies, most notably: a smooth dorsal margin of the parietal and widely opened choanae, interfenestral bar wide and strongly T-shaped instead of moderately T-shaped. In ''D. maghribensis'' the lateral and medial dorsal osteoderms are not sutured and have no serrated margin. The anterolateral margin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxillae
In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible (lower jaw), which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw. Anatomy Structure The maxilla is a paired bone - the two maxillae unite with each other at the intermaxillary suture. The maxilla consists of: * The body of the maxilla: pyramid-shaped; has an orbital, a nasal, an infratemporal, and a facial surface; contains the maxillary sinus. * Four processes: ** the zygomatic process ** the frontal process ** the alveolar process ** the palatine process It has three surfaces: * the anterior, posterior, medial Features of the maxilla include: * the infr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premaxillae
The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammals has been usually termed as the incisive bone. Other terms used for this structure include premaxillary bone or ''os premaxillare'', intermaxillary bone or ''os intermaxillare'', and Goethe's bone. Human anatomy In human anatomy, the premaxilla is referred to as the incisive bone (') and is the part of the maxilla which bears the incisor teeth, and encompasses the anterior nasal spine and alar region. In the nasal cavity, the premaxillary element projects higher than the maxillary element behind. The palatal portion of the premaxilla is a bony plate with a generally transverse orientation. The incisive foramen is bound anteriorly and laterally by the premaxilla and posteriorly by the palatine process of the maxilla. It is formed from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Naris
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External may refer to: * Externality, in economics, the cost or benefit that affects a party who did not choose to incur that cost or benefit * Externals, a fictional group of X-Men antagonists See also * *Internal (other) Internal may refer to: *Internality as a concept in behavioural economics *Neijia, internal styles of Chinese martial arts *Neigong or "internal skills", a type of exercise in meditation associated with Daoism * ''Internal'' (album) by Safia, 2016 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyrosaurus BW
''Dyrosaurus'' is a genus of extinct crocodylomorph that lived during the early Eocene. The name ''Dyrosaurus'' comes from () the Greek for lizard or reptile, and Dyr for Djebel Dyr (mountain) close to where the type species was discovered. It was a large reptile with an estimated body length of . Species Although the family Dyrosauridae is quite diverse and contains a variety of species, the genus ''Dyrosaurus'' has only two described species: ''D. phosphaticus'' and ''D. maghribensis''. ''D. phosphaticus'' was first discovered in Algeria and Tunisia whereas ''D. maghribensis'' has only been found in Morocco. ''D. maghribensis'' differs from ''D. phosphaticus'' by several synapomorphies, most notably: a smooth dorsal margin of the parietal and widely opened choanae, interfenestral bar wide and strongly T-shaped instead of moderately T-shaped. In ''D. maghribensis'' the lateral and medial dorsal osteoderms are not sutured and have no serrated margin. The anterolateral margin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous–Paleogene Extinction Event
The Cretaceous–Paleogene (K–Pg) extinction event, also known as the K–T extinction, was the extinction event, mass extinction of three-quarters of the plant and animal species on Earth approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs. Most other tetrapods weighing more than also became extinct, with the exception of some ectothermic species such as sea turtles and crocodilians. It marked the end of the Cretaceous period, and with it the Mesozoic era, while heralding the beginning of the current era, the Cenozoic. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the Cretaceous–Paleogene boundary, K–Pg boundary or K–T boundary, which can be found throughout the world in marine and terrestrial rocks. The boundary clay shows unusually high levels of the metal iridium, which is more common in asteroids than in the Earth's crust. As originally proposed in 1980 by a team of scientists le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodyliforms
Crocodyliformes is a clade of crurotarsan archosaurs, the group often traditionally referred to as "crocodilians". They are the first members of Crocodylomorpha to possess many of the features that define later relatives. They are the only pseudosuchians to survive the K-Pg extinction event. In 1988, James M. Clark argued that traditional names for well-known groups of animals should be restricted to their crown clades, that is, used only for natural groups comprising all living members of any given lineage and descendants of their closest common ancestor. This posed a problem for the crocodilians, because the name Crocodylia, while used in various ways by various scientists, had always included not only living crocodilians but many of their extinct ancestors known only from the fossil record.Benton, M.J. and Clark, J.M. (1988). "Archosaur phylogeny and the relationships of the Crocodylia." Pp. 295–338 in Benton, M.J. (ed.), ''The phylogeny and classification of the Tetrapods, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neosuchia
Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives. It is defined as the most inclusive clade containing all Crocodylomorpha, crocodylomorphs more closely related to ''Crocodylus niloticus'' (the Nile Crocodile) than to ''Notosuchus terrestris''. Members of Neosuchia generally share a crocodilian-like bodyform adapted to freshwater aquatic life, as opposed to the terrestrial habits of more basal crocodylomorph groups. The earliest neosuchian is suggested to be the Early Jurassic ''Calsoyasuchus'', which lived during the Sinemurian and Pliensbachian stages in North America. It is often identified as a member of Goniopholididae, though this is disputed, and the taxon may lie outside Neosuchia, which places the earliest records of the group in the Middle Jurassic. Characteristics Members of Neosuchia have a wide diversity of skull shapes. Several groups convergently evolved elongate gharial-like skulls, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and recover. As a species' potential Range (biology), range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxon, Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the Fossil, fossil record) after a period of apparent absence. Over five billion species are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryotes globally, possibly many times more if microorganisms are included. Notable extinct animal species include Dinosaur, non-avian dinosaurs, Machairodontinae, saber-toothed cats, and mammoths. Through evolution, species arise through the process of specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family (, : ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family—or whether a described family should be acknowledged—is established and decided upon by active taxonomists. There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
