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Pleurodira
The Pleurodira are one of the two living suborders of turtles, the other being the Cryptodira. The division between these two suborders represents a very deep evolutionary divide between two very different types of turtles. The physical differences between them, although anatomical and largely internal, are nonetheless significant, and the zoogeographic implications of them are substantial. The Pleurodira are known more commonly as the side-necked turtles and the name Pleurodira quite literally translates to side neck, whereas the Cryptodira are known as hidden-necked turtles. The Pleurodira turtles are currently restricted to freshwater habitats in the Southern Hemisphere, largely to Australia, South America, and Africa. Within the Pleurodira, three living families are represented: Chelidae, also known as the Austro-South American side-necked turtles, the Pelomedusidae, also known as the African mud terrapins, and the Podocnemididae, also known as the American side-neck rive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle Neck Retraction
Turtles are reptiles of the order Testudines, characterized by a special 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 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 carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates that join up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panpleurodira
The Pleurodira are one of the two living suborders of turtles, the other being the Cryptodira. The division between these two suborders represents a very deep evolutionary divide between two very different types of turtles. The physical differences between them, although anatomical and largely internal, are nonetheless significant, and the zoogeographic implications of them are substantial. The Pleurodira are known more commonly as the side-necked turtles and the name Pleurodira quite literally translates to side neck, whereas the Cryptodira are known as hidden-necked turtles. The Pleurodira turtles are currently restricted to freshwater habitats in the Southern Hemisphere, largely to Australia, South America, and Africa. Within the Pleurodira, three living families are represented: Chelidae, also known as the Austro-South American side-necked turtles, the Pelomedusidae, also known as the African mud terrapins, and the Podocnemididae, also known as the American side-neck river turt ... [...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] |
Podocnemididae
Podocnemididae is a family of pleurodire (side-necked) turtles, once widely distributed. Most of its 41 genera and 57 species are now extinct. Seven of its eight surviving species are native to South America: the genus '' Peltocephalus'', with two species, only one of which is extant (''P. dumerilianus'', the Big-headed Amazon River turtle); and the genus ''Podocnemis'', with six living species of South American side-necked river turtles and four extinct. There is also one genus native to Madagascar: '' Erymnochelys'', the Madagascan big-headed turtle, whose single species ''E. madagascariensis''. Like other pleurodire turtles, podocs have a "side-necked" defensive posture, turning the head sideways to hide it under the shell. Another characteristic of pleurodires is that the pelvis is fused to the shell which prevents pelvic motion, making it difficult to walk on land. Podocnemididae turtles live in aquatic environments and have shells streamlined to aid in swimming. The family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelidae
Chelidae is one of three living families of the turtle suborder Pleurodira, and are commonly called Austro-South American side-neck turtles. The family is distributed in Australia, New Guinea, parts of Indonesia, and throughout most of South America. It is a large family of turtles with a significant fossil history dating back to the Cretaceous. The family is entirely Gondwanan in origin, with no members found outside Gondwana, either in the present day or as a fossil.Georges, A. & Thomson, S. (2006). "Evolution and Zoogeography of Australian freshwater turtles". In: Merrick, J. R.; Archer, M.; Hickey, G. & Lee, M. (eds.) ''Evolution and Zoogeography of Australasian Vertebrates''. Sydney: Australia. Description Like all pleurodirous turtles, the chelids withdraw their necks sideways into their shells, differing from cryptodires that fold their necks in the vertical plane. They are all highly aquatic species with webbed feet and the capacity to stay submerged for long periods of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelodina
''Chelodina'', collectively known as snake-necked turtles, is a large and diverse genus of long-necked Chelidae, chelid turtles with a complicated Biological nomenclature, nomenclatural history. Although in the past, ''Macrochelodina'' and ''Macrodiremys'' have been considered separate genera and prior to that all the same, they are now considered subgenera of the ''Chelodina'', further ''Macrochelodina'' and ''Macrodiremys'' are now known to apply to the same species, hence ''Chelydera'' is used for the northern snake-necked turtles. ''Chelodina'' is an ancient group of Chelidae, chelid turtles native to Australia, New Guinea, the Indonesian Rote Island, and East Timor. The turtles within this subgenus are small to medium-sized with oval shaped carapace. They are side-necked turtles, meaning they tuck their head partially around the side of their body when threatened instead of directly backwards. ''Chelydera'' represents those species that have often been termed the ''Chelodina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Long-necked Turtle
The eastern long-necked turtle (''Chelodina longicollis''), also known as the common long-necked turtle and common snake-necked turtle, is an east Australian species of snake-necked turtle that inhabits a wide variety of water bodies and is an opportunistic feeder. It is a side-necked turtle (Pleurodira), meaning that it bends its head sideways into its shell rather than pulling it directly back. Naming ''Chelodina longicollis'' is a species of freshwater turtle, commonly known as the eastern long-necked turtle, common long-necked turtle, common snake-necked turtle.Kennett, R., Roe, J., Hodges, K., and Georges, A. 2009. ''Chelodina longicollis'' (Shaw 1784) – eastern long-necked turtle, common long-necked turtle, common snake-necked turtle. ''In'': Rhodin, A.G.J., Pritchard, P.C.H., van Dijk, P.P., Saumure, R.A., Buhlmann, K.A., Iverson, J.B., and Mittermeier, R.A. (Eds.). Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dortokidae
Dortokidae is an extinct family of freshwater pan- pleurodiran turtles, known from the Cretaceous and Paleocene of Europe. Only four species have been named, but indeterminate fossils show that they were abundant across western and eastern-central Europe during the Cretaceous. The family is only known from postcranial remains. Genera * '' Eodortoka'' Pérez-García, Gasulla, and Ortega 2014 Wessex Formation, United Kingdom Early Cretaceous (Hauterivian-Barremian)'''' Arcillas de Morella Formation, Spain, Early Cretaceous (Aptian) * ''Dortoka'' Lapparent de Broin and Murelaga, 1999 Laño site, Spain, (probably also present in southern France) Late Cretaceous (Campanian-Maastrichtian) Sînpetru Formation, Romania, Late Cretaceous (Maastrichtian) * ''Ronella'' Lapparent de Broin in Gheerbrant et al. 1999 Jibou Formation, Romania Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gular Scute
The turtle shell is a shield for the ventral and dorsal parts of turtles (the order Testudines), completely enclosing all the turtle's vital organs and in some cases even the head. It is constructed of modified bony elements such as the ribs, parts of the pelvis and other bones found in most reptiles. The bone of the shell consists of both skeletal and dermal bone, showing that the complete enclosure of the shell likely evolved by including dermal armor into the rib cage. The turtle's shell is an important study, not just because of the apparent protection it provides for the animal but also as an identification tool, in particular with fossils, as the shell is one of the likely parts of a turtle to survive fossilization. Hence understanding the shell structure in living species provides comparable material with fossils. The shell of the hawksbill turtle, among other species, has been used as a material for a wide range of small decorative and practical items since antiquity, in ... [...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] |
Araripemydidae
Araripemydidae is a family of freshwater aquatic turtles belonging to the order Pleurodira (side-necked turtles), known from the Early Cretaceous of South America and Africa. The family contains two recognised monotypic genera, ''Araripemys'' and '' Taquetochelys'', from the Santana Group of Brazil and the Elrhaz Formation of Niger, respectively, which date to the Aptian-Albian stages of the Early Cretaceous. They are consider to be the most basal lineage within the Pelomedusoides The Pleurodira are one of the two living suborders of turtles, the other being the Cryptodira. The division between these two suborders represents a very deep evolutionary divide between two very different types of turtles. The physical differenc .... They are thought to have been specialised suction feeders. ''Laganemys'' was named in 2013 but was later determined to be synonymous with ''Taquetochelys.'' References Late Cretaceous first appearances Paleocene extinctions Prehistoric turtle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelomedusidae
:''Alternatively, "Pelomedusidae" may refer to the Pelomedusoidea. See below for details.'' Pelomedusidae is a family of freshwater turtles endemic to sub-Saharan Africa, including Madagascar, São Tomé, and the Seychelles (although this population may have been introduced by humans). They range in size from in carapace length, and are generally roundish in shape. They are unable to fully withdraw their heads into their shells, instead drawing them to the side and folding them beneath the upper edge of their shells, hence are called African side-necked turtles. The family contains two living genera, '' Pelomedusa'' and '' Pelusios''. They are distinguished from their closest relatives by a hinge in the front section of the plastron.Obst, Fritz Jürgen (1998): elomedusinae ''In:'' Cogger, H.G., & Zweifel, R.G. (eds.): ''Encyclopedia of Reptiles and Amphibians'': 112-113. San Diego: Academic Press. . Pelomedusids spends most of their time in the mud at the bottom of rivers or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
