Sea turtles, 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. Six of the seven sea turtle species, all but the flatback, are present in U.S. waters, and are listed as endangered and/or threatened under the Endangered Species Act. All but the flatback turtle are listed as threatened with extinction globally on the IUCN Red List of Threatened Species. The flatback turtle is found only in the waters of Australia, Papua New Guinea, and Indonesia.
The leatherback sea turtle, sometimes called the lute turtle, leathery turtle or simply the luth, is the largest of all living turtles and the heaviest non-crocodilian reptile, reaching lengths of up to 2.7 metres and weights of 500 kilograms (1,100 lb). 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. Leatherback turtles have a global range, although there are multiple distinct subpopulations. The species as a whole is considered vulnerable, and some of its subpopulations are critically endangered.
Archelon is an extinct marine turtle from the Late Cretaceous, and is the largest turtle ever to have been documented, with the biggest specimen measuring 4.6 m (15 ft) from head to tail and 2.2–3.2 t in body mass. It is known only from the Pierre Shale and has one species, A. ischyros. In the past, the genus also contained A. marshii and A. copei, though these have been reassigned to Protostega and Kansastega, respectively. The genus was named in 1895 by American paleontologist George Reber Wieland based on a skeleton from South Dakota, who placed it into the extinct family Protostegidae. The leatherback sea turtle was once thought to be its closest living relative, but now, Protostegidae is thought to be a completely separate lineage from any living sea turtle.
The Cryptodira are a suborder of Testudines that includes most living tortoises and turtles. Cryptodira differ from Pleurodira 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.
Trionychia is a superfamily of turtles which encompasses the species that are commonly referred to as softshelled turtles as well as some others. The group contains two families, Carettochelyidae, which has only one living species, the pig-nosed turtle native to New Guinea and Northern Australia, and Trionychidae, the softshelled turtles, containing numerous species native to Asia, North America and Africa. These families likely diverged during the late Jurassic. The oldest known stem-trionychian is Sinaspideretes from the Late Jurassic of China.
Protostega is an extinct genus of sea turtle containing a single species, Protostega gigas. Its fossil remains have been found in the Smoky Hill Chalk formation of western Kansas, time-equivalent beds of the Mooreville Chalk Formation of Alabama and Campanian beds of the Rybushka Formation. Fossil specimens of this species were first collected in 1871, and named by Edward Drinker Cope in 1872. With a total length of 3.9 metres (13 ft), it is the second-largest sea turtle that ever lived, second only to the giant Archelon, and one of the three largest turtle of all time along Archelon and Gigantatypus.
Protostegidae is a family of extinct marine turtles that lived during the Cretaceous period. The family includes some of the largest sea turtles that ever existed. The largest, Archelon, had a head one metre (39 in) long. Like most sea turtles, they had flattened bodies and flippers for front appendages; protostegids had minimal shells like leatherback turtles of modern times.
Chrysaora colorata (Russell), commonly known as the purple-striped jelly or purple-striped sea nettle, is a species of jellyfish that exists primarily off the coast of California from Bodega Bay to San Diego. The bell (body) of the jellyfish is up to 70 cm (2.3 ft) in diameter, typically with a radial pattern of stripes. The tentacles vary with the age of the individual, consisting typically of eight marginal long dark arms, and four central frilly oral arms. It is closely studied by scientists due to not much being known about their eating habits. A 15-foot-long specimen has been seen.
Corsochelys is an extinct genus of sea turtle that lived in the Late Cretaceous (Campanian). Zangerl (1960) named the type species, based upon remains found in Alabama within the Mooreville Chalk Formation.
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 seven species, P. polygonus, P. calvertensis, P. eocaenus, P. oregonesis, P. californiensis, P. rupeliensis, P. scaldii, and a species discovered in 1995, P. terrypratchetti.
Mesodermochelys is an extinct genus of sea turtle known from the Campanian to the Maastrichtian of what today is Japan and from the Maastrichtian of Chile. One species is known, the type species M. undulatus; it was given its binomial name by Ren Hirayama and Tsutomu Chitoku in 1996. Studies of its skull indicate that it was a primitive member of the Dermochelyidae that was closely related to the Protostegidae. It has been described as the best representative of Mesozoic dermochelyids.
Chan Eng Heng is a Malaysian turtle conservationist. She is a retired professor from Universiti Malaysia Terengganu,who has been recognised by the United Nations Environment Program for her efforts to protect sea turtles.
The African dwarf mud turtle is a species of turtle in the family Pelomedusidae. It is endemic to Africa : in Angola, the Democratic Republic of the Congo, Malawi, and Zambia. These mud turtles are the smallest of all African turtle species, “Nanus” which they are referred to are one of the 3 smallest turtle species in the world. The other two are Stink Pot Musk and Muhlenberg's Bog Turtles. All 3 species barely reach 4 inches as full grown adults. Like many of the world's chelonians, Pelusios castaneus has the potential to live a long life. Reports typically suggest more than 50 years in captivity for this species.
Pancheloniidae is a clade of sea turtles It is defined as all turtles more closely related to cheloniid sea turtles than to dermochelyid ("leatherback") sea turtles.
Rhinochelys is an extinct genus of sea turtles belonging to the family Protostegidae.
The Amana Nature Reserve is a nature reserve in French Guiana, France. It has been protected because it is one of the world's largest leatherback sea turtle nesting sites. It is part of the communes of Awala-Yalimapo and Mana.
