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Testudinoid
Testudinoidea is a superfamily within the suborder Cryptodira of the order Testudines. It includes the pond turtles (Family: Emydidae), Asian turtles (Family: Geoemydidae), the monotypic big-headed turtle (Family: Platysternidae), and the tortoises (Family: Testudinidae). Systematics A 2021 study found the clade to be divided into two extant groups: Testuguria, containing Geoemydidae and Testudinidae; and Emysternia, containing Emydidae and Platysternidae. The extinct Lindholmemydidae, formerly classified in Testudinoidea, may fall outside the crown group of Testudinoidea, although there is not yet enough evidence for this. * Pantestudinoidea ** Lindholmemydidae? **Testudinoidea ***'' Wutuchelys'' *** Haichemydidae *** Sinochelyidae *** Testuguria **** Geoemydidae **** Testudinidae *** Emysternia **** Emydidae **** Platysternidae The big-headed turtle (''Platysternon megacephalum'') is a species of turtle in the family Platysternidae from Southeast Asia and southern Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wutuchelys
''Wutuchelys'' is an extinct genus of testudinoid that lived during the Ypresian stage of the Eocene epoch. Distribution ''Wutuchelys eocenica'' is known from the Wutu Formation of Shandong Shandong is a coastal Provinces of China, province in East China. Shandong has played a major role in Chinese history since the beginning of Chinese civilization along the lower reaches of the Yellow River. It has served as a pivotal cultural ..., China. References {{Taxonbar, from1=Q134893000, from2=Q134892995 Eocene reptiles of Asia Monotypic prehistoric reptile genera Fossils of China Fossil taxa described in 2019 Testudinoidea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptodira
The Cryptodira (') are a suborder of Testudines that includes most living tortoises and turtles. Cryptodira is commonly called the "Hidden-Neck Turtles" or the "Inside-Neck Turtles". Cryptodira differ from Pleurodira (side-necked turtles) in that they lower their necks and pull the heads straight back into the shells, instead of folding their necks sideways along the body under the shells' marginals. They include among their species freshwater turtles, snapping turtles, tortoises, softshell turtles, and sea turtles. Neck retraction The Cryptodira are characterized by retraction of the head in the vertical plane, which permits for primarily vertical movements and restricted lateral movements outside of the shell. These motions are largely due to the morphology and arrangement of cervical vertebrae. In all recent turtles, the cervical column consists of nine joints and eight vertebrae. Compared to the narrow vertebrae and the closely positioned zygapophyses of the pleur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lindholmemydidae
Lindholmemydidae is an extinct family of turtles in the Testudinoidea. Genera *'' Amuremys'' *'' Elkemys'' *'' Gravemys'' *'' Hongilemys'' *'' Khodzhakulemys'' *'' Mongolemys'' *'' Paragravemys'' *'' Paramongolemys'' *'' Shandongemys'' References Testudinoidea Extinct turtles {{paleo-turtle-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midland Painted Turtle
The painted turtle (''Chrysemys picta'') is the most widespread native turtle of North America. It lives in relatively slow-moving fresh waters, from southern Canada to northern Mexico, and from the Atlantic to the Pacific. They have been shown to prefer large wetlands with long periods of inundation and emergent vegetation. This species is one of the few that is specially adapted to tolerate freezing temperatures for extended periods of time due to an antifreeze-like substance in their blood that keeps their cells from freezing. This turtle is a member of the genus ''Chrysemys'', which is part of the pond turtle family Emydidae. Fossils show that the painted turtle existed 15 million years ago. Three regionally based subspecies (the eastern, midland, and western) evolved during the Last glacial period, last ice age. The southern painted turtle (''C. dorsalis'') is alternately considered the only other species in ''Chrysemys'', or another subspecies of ''C. picta'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tortoise
Tortoises ( ) are reptiles of the family Testudinidae of the order Testudines (Latin for "tortoise"). Like other turtles, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like other members of the suborder Cryptodira, they retract their necks and heads directly backward into the shell to protect them. Tortoises can vary in size with some species, such as the Galápagos giant tortoise, growing to more than in length, whereas others like the Speckled cape tortoise have shells that measure only long. Several lineages of tortoises have independently evolved very large body sizes in excess of , including the Galapagos giant tortoise and the Aldabra giant tortoise. They are usually diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals. Tortoises are the longest-living land animals in the world, although the longest-living species of tortois ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big-headed Turtle
The big-headed turtle (''Platysternon megacephalum'') is a species of turtle in the family Platysternidae from Southeast Asia and southern China. Background Previously considered a distinct family placed on occasion in " Kinosternoidea", it was later moved to the Emydidae. This, as well as the subfamily and the genus ''Platysternon'', are monotypic. The big-headed turtle is named after its disproportionately large head which leads to an inability to retreat into its shell. In order to protect itself it instead has an armored head and sharp beak. Distribution The big-headed turtle is found in Cambodia, China, Laos, Myanmar, Thailand, and Vietnam. It is commonly found in fast flowing streams and waterfalls in rocky areas Behaviour The big-headed turtle is known to readily climb over obstacles in and around rivers and fast streams, using its tail as a prop to extend the reach of its strong claws. It also uses its beak to assist in climbing. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Taxon
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of Genus, genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testudines
Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other Amniote, amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed Turtle shell#Carapace, carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scale (anatomy), scales made of keratin, the material of hair, horns, and claws. The carapace bones deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superfamily (taxonomy)
In biology, taxonomic rank (which some authors prefer to call nomenclatural rank because ranking is part of nomenclature rather than taxonomy proper, according to some definitions of these terms) is the relative or absolute level of a group of organisms (a ''taxon'') in a hierarchy that reflects evolutionary relationships. Thus, the most inclusive clades (such as Eukarya and Animalia) have the highest ranks, whereas the least inclusive ones (such as ''Homo sapiens'' or ''Bufo bufo'') have the lowest ranks. Ranks can be either relative and be denoted by an indented taxonomy in which the level of indentation reflects the rank, or absolute, in which various terms, such as species, genus, family, order, class, phylum, kingdom, and domain designate rank. This page emphasizes absolute ranks and the rank-based codes (the Zoological Code, the Botanical Code, the Code for Cultivated Plants, the Prokaryotic Code, and thCode for Viruses require them. However, absolute ranks are not req ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emydidae
Emydidae (Latin (freshwater tortoise) + Ancient Greek (, "appearance, resemblance")) is a family of testudines (turtles) that includes close to 50 species in 10 genera. Members of this family are commonly called terrapins, pond turtles, or marsh turtles. Several species of Asian box turtles were formerly classified in the family; however, revised taxonomy has separated them to a different family ( Geoemydidae). As currently defined, the Emydidae are entirely a Western Hemisphere family, with the exception of two species of pond turtle. Description The upper shell (carapace) of most emydids is the shape of a low arch, although in some species, it is domed. The upper shell may have one or two ridges that run from front to the back of the animal (a projection commonly called a "keel"), or such a feature may be absent. A prominent bridge often connects the top shell to the bottom shell (plastron). Emydids have large bottom shells, and some members of the family have a movable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
