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Chelonioidea
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, Kemp's ridley, and olive ridley sea turtles. All six of the sea turtle species present in US waters (all of those listed above except the flatback) are listed as endangered and/or threatened under the Endangered Species Act. The seventh sea turtle species is the flatback, which exists in the waters of Australia, Papua New Guinea and Indonesia. Sea turtles can be separated into the categories of hard-shelled (cheloniid) and leathery-shelled ( dermochelyid).Wyneken, J. 2001. The Anatomy of Sea Turtles. U.S Department of Commerce NOAA Technical Memorandum NMFS-SEFSC-470, 1-172 pp. There is only one dermochelyid species which is the leatherback sea turtle. Description For each of the seven types of sea turtles, females and males are the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kemp's Ridley Sea Turtle
Kemp's ridley sea turtle (''Lepidochelys kempii''), also called the Atlantic ridley sea turtle, is the rarest species of sea turtle and is the world's most endangered species of sea turtle. It is one of two living species in the genus '' Lepidochelys'' (the other one being ''L. olivacea'', the olive ridley sea turtle). Taxonomy This species of turtle is called Kemp's ridley because Richard Moore Kemp (1825–1908) of Key West was the first to send a specimen to Samuel Garman at Harvard, but the origin of the name "ridley" itself is unknown. Prior to the term being popularly used (for both species in the genus), ''L. kempii'' at least was known as the "bastard turtle". At least one source also refers to Kemp's ridley as a "heartbreak turtle". In her book ''The Great Ridley Rescue'', Pamela Philips claimed the name was coined by fishermen who witnessed the turtles dying after being "turned turtle" (on their backs). The fishermen said the turtles "died of a broken heart". Descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leatherback Sea Turtle
The leatherback sea turtle (''Dermochelys coriacea''), sometimes called the lute turtle or leathery turtle or simply the luth, is the largest of all living turtles and the heaviest non-crocodilian reptile, reaching lengths of up to and weights of . It is the only living species in the genus ''Dermochelys'' and family Dermochelyidae. It can easily be differentiated from other modern sea turtles by its lack of a bony shell; instead, its carapace is covered by oily flesh and flexible, leather-like skin, for which it is named. Taxonomy and evolution Taxonomy ''Dermochelys coriacea'' is the only species in genus ''Dermochelys''. The genus, in turn, contains the only extant member of the family Dermochelyidae. Domenico Agostino Vandelli named the species first in 1761 as ''Testudo coriacea'' after an animal captured at Ostia and donated to the University of Padua by Pope Clement XIII. In 1816, French zoologist Henri Blainville coined the term ''Dermochelys''. The leatherback was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptodira
The Cryptodira ('' el, hidden neck'') are a suborder of Testudines that includes most living tortoises and 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 pleurodires, the cryptodires’ vertebrae take on the opposite shape. Their ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dermochelyidae
Dermochelyidae is a family of turtles which has seven extinct genera and one extant genus, including the largest living sea turtles. Classification of known genera The following list of dermochelyid species was published by Hirayama and Tong in 2003, unless otherwise noted. * ''Arabemys crassiscutata'' * †''Eosphargis breineri'' * ''Mesodermochelys undulatus'' *Subfamily Dermochelyinae ** †''Cosmochelys'' ** ''Dermochelys coriacea'' – leatherback sea turtle ** †''Psephophorus ''Psephophorus'' is an extinct genus of sea turtle that lived from the Oligocene to the Pliocene. Its remains have been found in Europe, Africa, North America, and New Zealand. It was first named by Hermann von Meyer in 1847, and contains seve ...'' Phylogeny Evers et al. (2019): References Bibliography * External linksFamily Dermochelyidae (Leatherback turtles) from Turtles of the World by C.H. Ernst, R.G.M. Altenburg & R.W. Barbour {{Taxonbar, from=Q2738058 Taxa named by Leopo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheloniidae
Cheloniidae is a family of typically large marine turtles that are characterised by their common traits such as, having a flat streamlined wide and rounded shell and almost paddle-like flippers for their forelimbs. They are the only sea turtles to have stronger front limbs than back limbs. The six species that make up this family are: the green sea turtle, loggerhead sea turtle, olive ridley sea turtle, hawksbill sea turtle, flatback sea turtle and the Kemp's ridley sea turtle. Morphology In contrast to their earth-bound relatives, tortoises, sea turtles do not have the ability to retract their heads into their shells. Their plastron, which is the bony plate making up the underside of a turtle or tortoise's shell, is comparably more reduced from other turtle species and is connected to the top part of the shell by ligaments without a hinge separating the pectoral and abdominal plates of the plastron. Sizes among the seven species of sea turtles range from 71 to 213 cm; for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testudines
Turtles are an order (biology), order of reptiles known as 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 bon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flatback Sea Turtle
The Australian flatback sea turtle (''Natator depressus'') is a species of sea turtle in the family Cheloniidae. The species is endemic to the sandy beaches and shallow coastal waters of the Australian continental shelf. This turtle gets its common name from the fact that its shell has a flattened or lower dome than the other sea turtles. It can be olive green to grey with a cream underside. It averages from 76 to 96 cm (30 to 38 inches) in carapace length and can weigh from 70 to 90 kg (154 to 198 lb). The hatchlings, when emerging from nests, are larger than other sea turtle hatchlings when they hatch. The flatback turtle is listed by the IUCN Red List of Threatened Species as data deficient, meaning there is insufficient scientific information to determine its conservation status at this time. It was previously listed as vulnerable in 1994. It is not as threatened as other sea turtles due to its small dispersal range. This animal can be 31 to 37 inches long and abou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle
Turtles are an order of reptiles known as 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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loggerhead Sea Turtle
The loggerhead sea turtle (''Caretta caretta'') is a species of oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around in carapace length when fully grown. The adult loggerhead sea turtle weighs approximately , with the largest specimens weighing in at more than . The skin ranges from yellow to brown in color, and the shell is typically reddish brown. No external differences in sex are seen until the turtle becomes an adult, the most obvious difference being the adult males have thicker tails and shorter plastrons (lower shells) than the females. The loggerhead sea turtle is found in the Atlantic, Pacific, and Indian Oceans, as well as the Mediterranean Sea. It spends most of its life in saltwater and estuarine habitats, with females briefly coming ashore to lay eggs. The loggerhead sea turtle has a low reproductive rate; females lay an average of four egg clutches and then become ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurodire
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 tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, ''Malm'' was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units. Subdivisions The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock: Paleogeography During the Late Jurassic Epoch, Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the spawning of the Atlantic Ocean. However, at this time, the Atlantic Ocean was relatively narrow. Life forms of the epoch This epoch is well known for many famous types of dinosau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiochelys
''Plesiochelys'' is a genus of late Jurassic European and Asian turtle. The type species is ''Plesiochelys etalloni''. Fossil records have discovered ''Plesiochelys bigleri'' and ''Plesiochelys etalloni'' from the Kimmeridge Clay of England and outside the Swiss and French Jura Mountains. A recent studyEvers, S. W., & Benson, R. B. (2019). A new phylogenetic hypothesis of turtles with implications for the timing and number of evolutionary transitions to marine lifestyles in the group. ''Palaeontology'', 62(1), 93-134. placed ''Plesiochelys'' as an Angolachelonia and outside Testudines Turtles are an order (biology), order of reptiles known as 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) an .... References Sources *Gaffney, Eugene S. "A taxonomic revision of the Jurassic turtles Portlandemys and Plesiochelys. ''American Museum Nov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
