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Feature Scales (zoology)
Feature scales are enlarged scales found on various reptiles. Despite their close resemblance to osteoderms, they have no boney component to them. Examples of reptiles that are known to possess feature scales are Iguanas, and many non-avian dinosaurs such as Carnotaurus, Brachylophosaurus, Diplodocids, and Ceratopsians. The term was first coined by Phil R. Bell in 2012 in reference to the midline scutes of the Hadrosaurid Saurolophus. Feature scales are distinguished from basement scales (typical, small scales that make up most of the overall scales), by their notable size difference, being significantly larger. See also * Scale (zoology) * Osteoderm * Reptile scales * Scute A scute () or scutum (Latin: ''scutum''; plural: ''scuta'' "Scutum (shield), shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of Bird anatomy#Scales, birds. The ter ... References Scales {{Reptile-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoderms
Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of Extant taxon, extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, Temnospondyli, temnospondyls (extinct amphibians), various groups of dinosaurs (most notably ankylosaurs and stegosaurians), phytosaurs, aetosaurs, placodonts, and hupehsuchians (marine reptiles with possible ichthyosaur affinities). Osteoderms are uncommon in mammals, although they have occurred in many xenarthrans (armadillos and the extinct glyptodonts and Mylodontidae, mylodontid ground sloths). The heavy, bony osteoderms have evolved independently in many different lineages. The armadillo osteoderm is believed to develop in subcutaneous dermal tissues. These varied structures should be thought of as anatomical analogues, not homology (biology), homologues, and do not necessarily indicate monophyly. The structures are however derived from scute, sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguanas
''Iguana'' (, ) is a genus of herbivorous lizards that are native to tropical areas of Mexico, Central America, South America, and the Caribbean. The genus was first described by Austrian naturalist J.N. Laurenti in 1768. Two species are placed in the genus: The green iguana, which is widespread throughout its range and a popular pet; and the Lesser Antillean iguana, which is native to the Lesser Antilles. Genetic analysis indicates that the green iguana may comprise a complex of multiple species, some of which have been recently described, but the Reptile Database considers all of these as subspecies of the green iguana. The word "iguana" is derived from the original Taino name for the species, ''iwana''. In addition to the two species in the genus ''Iguana'', several other related genera in the same family have common names of the species including the word "iguana". The species is a popular quarry for pets, and non-native animals have been widely introduced beyond its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaurs
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutionary history, evolution of dinosaurs is a subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, Evolution of birds, having evolved from earlier Theropoda, theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomy (biology), taxonomic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnotaurus
''Carnotaurus'' (; ) is a genus of Theropoda, theropod dinosaur that lived in South America during the Late Cretaceous period, probably sometime between 72 and 69 million years ago. The only species is ''Carnotaurus sastrei''. Known from a single well-preserved skeleton, it is one of the best-understood theropods from the Southern Hemisphere. The skeleton, found in 1984, was uncovered in the Chubut Province of Argentina from rocks of the La Colonia Formation. ''Carnotaurus'' is a derived member of the Abelisauridae, a group of large theropods that occupied the large predation, predatorial ecological niche, niche in the southern landmasses of Gondwana during the late Cretaceous. Within the Abelisauridae, the genus is often considered a member of the Brachyrostra, a clade of short-snouted forms restricted to South America. ''Carnotaurus'' was a lightly built, bipedal predator, measuring in length and weighing . As a theropod, ''Carnotaurus'' was highly specialized and distincti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachylophosaurus
''Brachylophosaurus'' ( or ) is a genus of hadrosaurid dinosaur that lived during the Late Cretaceous period of western North America. It was first named in 1953 by Charles Mortram Sternberg for a skull and skeleton he discovered in 1936 in the Oldman Formation of Alberta, Canada, for which he named the new taxon ''Brachylophosaurus canadensis''. While this single specimen was the only known material of ''Brachylophosaurus'' for a long time, extensive discoveries in the Judith River Formation of Montana, USA have uncovered not only additional skulls and skeletons with extensive impressions of skin, but also a bonebed of 800 specimens. The earliest of these discoveries in Montana was named ''Brachylophosaurus goodwini'' by John R. Horner, but it is now believed that there was only a single species of ''Brachylophosaurus'', with ''B. goodwini'' as either a junior synonym of ''B. canadensis'' or an indeterminate member of Brachylophosaurini. It is known from several skeletons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplodocids
Diplodocids, or members of the family Diplodocidae ("double beams"), are a group of sauropod dinosaurs. The family includes some of the longest creatures ever to walk the Earth, including ''Diplodocus'' and '' Supersaurus'', some of which may have reached lengths of up to . Description Diplodocids were generally large animals, even by sauropod standards. Thanks to their long necks and tails, diplodocids were among the longest sauropods, with some species such as '' Supersaurus vivianae'' and '' Diplodocus hallorum'' estimated to have reached lengths of or more. The heaviest diplodocids, such as ''Supersaurus'' and ''Apatosaurus'', may have weighed close to 40 tonnes. However, not all diplodocids were so large; the South American species '' Leinkupal laticauda'' was one of the smallest diplodocids, with an estimated length of only . Their heads, like those of other sauropods, were tiny with the nasal openings on the top of the head (though in life the nostrils themselves would h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopsians
Ceratopsia or Ceratopia ( or ; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Asia and Europe, during the Cretaceous Period, although ancestral forms lived earlier, in the Late Jurassic of Asia. The earliest known ceratopsian, '' Yinlong downsi'', lived between 161.2 and 155.7 million years ago.Holtz, Thomas R. Jr. (2011) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,'Winter 2010 Appendix./ref> The last ceratopsian species, '' Triceratops prorsus'', became extinct during the Cretaceous–Paleogene extinction event, . ''Triceratops'' is by far the best-known ceratopsian to the general public. It is traditional for ceratopsian genus names to end in "''-ceratops''", although this is not always the case. One of the first named genera was '' Ceratops'' itself, which lent its name to the group, although it is considered a ''nomen dubium'' today as its fossil remains have no disting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadrosaurid
Hadrosaurids (), also hadrosaurs or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as ''Edmontosaurus'' and ''Parasaurolophus'', was a common group of herbivores during the Late Cretaceous Period (geology), Period. Hadrosaurids are descendants of the Late Jurassic/Early Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, and South America. Like other ornithischians, hadrosaurids had a Glossary of dinosaur anatomy#predentary, predentary bone and a pubic bone which was positioned backwards in the pelvis. Unlike more primitive iguanodonts, the teeth of hadrosaurids are stacked into complex s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saurolophus
''Saurolophus'' (; meaning "lizard crest") is a genus of large hadrosaurid dinosaur from the Late Cretaceous period of Asia and North America, that lived in what is now the Horseshoe Canyon and Nemegt formations about 70 million to 66 million years ago. It is one of the few genera of dinosaurs known from multiple continents. The type species, ''S. osborni'', was described by Barnum Brown in 1912 from Canadian fossils. A second valid species, ''S. angustirostris'', is represented by numerous specimens from Mongolia, and was described by Anatoly Konstantinovich Rozhdestvensky. ''Saurolophus'' is distinguished by a spike-like crest which projects up and back from the skull. It was a herbivorous dinosaur which could move about either bipedally or quadrupedally. Discovery and history Barnum Brown recovered the first described remains of ''Saurolophus'' in 1911, including a nearly complete skeleton ( AMNH 5220). Now on display in the American Museum of Natural History, this skelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scale (zoology)
In zoology, a scale (; ) is a small rigid plate (animal anatomy), plate made out of keratin that grows out of Vertebrate animals' skin to provide protection. In lepidopterans (butterflies and moths), scales are plates on the surface of the insect wing, made out of chitin instead of keratin, and provide coloration. Scales are quite common and have evolved multiple times through convergent evolution, with varying structure and function. Scales are generally classified as part of an organism's integumentary system. There are various types of scales according to the shape and class (biology), class of an animal. Fish scales Fish scales are skin, dermally derived, specifically in the mesoderm. This fact distinguishes them from reptile scales paleontologically. Genetically, the same genes involved in tooth and hair development in mammals are also involved in scale development. File:Ganoid scales.png, Ganoid scales on a carboniferous fish ''Amblypterus striatus'' File:Denticules cutan� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoderm
Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amphibians), various groups of dinosaurs (most notably ankylosaurs and stegosaurians), phytosaurs, aetosaurs, placodonts, and hupehsuchians (marine reptiles with possible ichthyosaur affinities). Osteoderms are uncommon in mammals, although they have occurred in many xenarthrans (armadillos and the extinct glyptodonts and mylodontid ground sloths). The heavy, bony osteoderms have evolved independently in many different lineages. The armadillo osteoderm is believed to develop in subcutaneous dermal tissues. These varied structures should be thought of as anatomical analogues, not homologues, and do not necessarily indicate monophyly. The structures are however derived from scutes, common to all classes of amniotes and are an exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
