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Prorotodactylus
''Prorotodactylus'' is a dinosauromorph or pterosauromorph ichnogenus known from fossilized footprints found in Poland and France. The prints may have been made by a dinosauromorph that was a precursor to the dinosaurs, possibly closely related to '' Lagerpeton''. Fossils of ''Prorotodactylus'' date back to the early Olenekian stage of the Early Triassic, making it the oldest known dinosauromorph. Its presence during this time extends the range of the dinosaur stem lineage to the start of the Early Triassic, soon after the Permian-Triassic extinction event. ''Prorotodactylus'' is the only ichnogenus within the ichnofamily Prorotodactylidae. Two ichnospecies are known, the type ''P. mirus'' and ''P. lutevensis''. Specimens ''Prorotodactylus mirus'', the type ichnospecies, has been found in the Holy Cross Mountains in Poland. It was named in 2000, with the specific name meaning "strange" in Latin in reference to unusual features in forefoot imprints. A second ichnospecies, ''P. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagerpeton
''Lagerpeton'' is a genus of lagerpetid avemetatarsalian, comprising a single species, ''L. chanarensis''. First described from the Chañares Formation of Argentina by A. S. Romer in 1971, ''Lagerpeton'' anatomy is somewhat incompletely known, with fossil specimens accounting for the pelvic girdle, hindlimbs, posterior presacral, sacral and anterior caudal vertebrae. Skull and shoulder material has also been described. The name comes from the Greek (, "hare") plus (, "reptile"). Discovery ''Lagerpeton'' fossils have only been collected from the Chañares Formation in La Rioja Province, Argentina. The first of these fossils were discovered in a 1964-1965 expedition by the Museum of Comparative Zoology (MCZ) and Museo de la Plata (MLP), although some were also discovered in 1966 by paleontologists from the Miguel Lillo Institute (PVL) of the University of Tucuman. Alfred Romer named ''Lagerpeton chanarensis'' in 1971, based on a complete right hindlimb discovered dur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosauromorph
Dinosauromorpha is a clade of avemetatarsalian archosaurs (reptiles 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 Avemet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georges Demathieu
Georges may refer to: Places *Georges River, New South Wales, Australia *Georges Quay (Dublin) *Georges Township, Fayette County, Pennsylvania Other uses *Georges (name) * ''Georges'' (novel), a novel by Alexandre Dumas * "Georges" (song), a 1977 song originally recorded by Pat Simon and covered by Sylvie Vartan *Georges (store), a department store in Melbourne, Australia from 1880 to 1995 * Georges (''Green Card'' character) People with the surname * Eugenia Georges, American anthropologist *Karl Ernst Georges (1806–1895), German classical philologist and lexicographer, known for his edition of Latin-German dictionaries. See also *École secondaire Georges-P.-Vanier, a high school in Hamilton, Ontario, Canada *École secondaire Georges-Vanier in Laval, Quebec, Canada * French cruiser ''Georges Leygues'', commissioned in 1937 * French frigate ''Georges Leygues'' (D640), commissioned in 1979 *George (other) *Georges Creek (other) *Georges Creek Coal and Iron Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, the fourth-largest country in the Americas, and the eighth-largest country in the world. It shares the bulk of the Southern Cone with Chile to the west, and is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. Argentina is a federal state subdivided into twenty-three provinces, and one autonomous city, which is the federal capital and largest city of the nation, Buenos Aires. The provinces and the capital have their own constitutions, but exist under a federal system. Argentina claims sovereignty over the Falkland Islands, South Georgia and the South Sandwich Islands, and a part of Antarctica. The earliest recorded human prese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metatarsal
The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medial side (the side of the great toe): the first, second, third, fourth, and fifth metatarsal (often depicted with Roman numerals). The metatarsals are analogous to the metacarpal bones of the hand. The lengths of the metatarsal bones in humans are, in descending order, second, third, fourth, fifth, and first. Structure The five metatarsals are dorsal convex long bones consisting of a shaft or body, a base (proximally), and a head (distally).Platzer 2004, p. 220 The body is prismoid in form, tapers gradually from the tarsal to the phalangeal extremity, and is curved longitudinally, so as to be concave below, slightly convex above. The base or posterior extremity is wedge-shaped, articulating proximally with the tarsal bones, and by it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digitigrade
In terrestrial vertebrates, digitigrade () locomotion is walking or running on the toes (from the Latin ''digitus'', 'finger', and ''gradior'', 'walk'). A digitigrade animal is one that stands or walks with its toes (metatarsals) touching the ground, and the rest of its foot lifted. Digitigrades include walking birds (what many assume to be bird knees are actually ankles), cats, dogs, and many other mammals, but not plantigrades or unguligrades. Digitigrades generally move more quickly and quietly than other animals. There are anatomical differences between the limbs of plantigrades, like humans, and both unguligrade and digitigrade limbs. Digitigrade and unguligrade animals have relatively long carpals and tarsals, and the bones which would correspond to the human ankle are thus set much higher in the limb than in a human. In a digitigrade animal, this effectively lengthens the foot, so much so that what are often thought of as a digitigrade animal's "hands" and "feet" correspon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chirotherium
''Chirotherium'', also known as ''Cheirotherium'' (‘hand-beast’), is a Triassic trace fossil consisting of five-fingered (pentadactyle) footprints and whole tracks. These look, by coincidence, remarkably like the hands of apes and bears, with the outermost toe having evolved to extend out to the side like a thumb, although probably only functioning to provide a firmer grip in mud. ''Chirotherium'' tracks were first found in 1834 in Lower Triassic sandstone (Buntsandstein) in Thuringia, Germany, dating from about 243 million years ago ( mya). The creatures who made the footprints and tracks were probably pseudosuchian archosaurs related to the ancestors of the crocodiles. They likely belonged to either prestosuchidae or rauisuchidae groups, which were both large carnivores with semi-erect gaits. History ''Chirotherium'' tracks were first found in German Triassic sandstones in 1834, and later in England in 1838. They were found before dinosaurs were known and initial models o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pes (zoology)
The pes (Latin for ''foot'') is the zoological term for the distal portion of the hind limb of tetrapod animals. It is the part of the pentadactyl limb that includes the metatarsals and digits (phalanges). During evolution, it has taken many forms and served a variety of functions. It can be represented by the foot of primates, the lower hind limb of hoofed animals, the lower portion of the leg of dinosaurs including birds or the rear paw. It is also represented in the rear 'paddle' of extinct marine reptiles, such as plesiosaurs. The oldest types of tetrapods had seven or eight digits. See also *Manus (anatomy) The manus (Latin for ''hand'', plural manus) is the zoological term for the distal portion of the fore limb of an animal. In tetrapods, it is the part of the pentadactyl limb that includes the metacarpals and digits (phalanges). During evolution, ... References Vertebrate anatomy Dinosaur anatomy Lower limb anatomy {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spathian
In the geologic timescale, the Olenekian is an age in the Early Triassic epoch; in chronostratigraphy, it is a stage in the Lower Triassic series. It spans the time between Ma and Ma (million years ago). The Olenekian is sometimes divided into the Smithian and the Spathian subages or substages. The Olenekian follows the Induan and is followed by the Anisian (Middle Triassic). The Olenekian saw the deposition of a large part of the Buntsandstein in Europe. The Olenekian is roughly coeval with the regional Yongningzhenian Stage used in China. Stratigraphic definitions The Olenekian Stage was introduced into scientific literature by Russian stratigraphers in 1956. The stage is named after Olenëk in Siberia. Before the subdivision in Olenekian and Induan became established, both stages formed the Scythian Stage, which has since disappeared from the official timescale. The base of the Olenekian is at the lowest occurrence of the ammonoids '' Hedenstroemia'' or '' Meekoceras gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetostratigraphy
Magnetostratigraphy is a geophysical correlation technique used to date sedimentary and volcanic sequences. The method works by collecting oriented samples at measured intervals throughout the section. The samples are analyzed to determine their ''characteristic remanent magnetization'' (ChRM), that is, the polarity of Earth's magnetic field at the time a stratum was deposited. This is possible because volcanic flows acquire a thermoremanent magnetization and sediments acquire a depositional remanent magnetization, both of which reflect the direction of the Earth's field at the time of formation. This technique is typically used to date sequences that generally lack fossils or interbedded igneous rock. Technique When measurable magnetic properties of rocks vary stratigraphically they may be the basis for related but different kinds of stratigraphic units known collectively as ''magnetostratigraphic units (magnetozones)''. The magnetic property most useful in stratigraphic work is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
