Turtles are an order of reptiles known as Testudines, characterized by a shell developed mainly from their ribs. Modern turtles are divided into two major groups, the side-necked turtles and hidden neck turtles which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including tortoises and terrapins. They are found on most continents, some islands and much of the ocean. Like other reptiles, birds, and mammals, they breathe air and do not lay eggs underwater, although many species live in or around water. Genetic evidence typically places them in close relation to crocodilians and birds.
Teenage Mutant Ninja Turtles is an entertainment franchise created by American comic book authors Kevin Eastman and Peter Laird. It follows Leonardo, Raphael, Donatello and Michelangelo, four anthropomorphic turtle brothers trained in ninjitsu who fight evil in New York City.
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 green sea turtle, loggerhead sea turtle, Kemp's ridley sea turtle, olive ridley sea turtle, hawksbill sea turtle, flatback sea turtle, and leatherback sea turtle. All six of the sea turtle species present in US waters 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). There is only one dermochelyid species which is the leatherback sea turtle.
Sauria is the clade containing the most recent common ancestor of archosaurs and lepidosaurs, and all its descendants. Assuming turtles lie within Sauria, the group can be considered the crown group of diapsids, or reptiles in general. Recent genomic studies and comprehensive studies in the fossil record suggest that turtles are closely related to archosaurs, not to the pre-Saurian parareptiles as previously thought. Sauria includes all modern reptiles as well as various extinct groups. Sauria lies within the larger total group Sauropsida, which also contains various stem-reptiles which are more closely related to reptiles than to mammals. Prior to its modern usage, "Sauria" was used as a name for the suborder occupied by lizards, which before 1800 were considered crocodilians.
Diapsids are a group of amniote tetrapods that developed two holes in each side of their skulls about 300 million years ago during the late Carboniferous period. The diapsids are extremely diverse, and include all crocodilians, lizards, snakes, tuatara, turtles, and birds. Although some diapsids have lost either one hole (lizards), or both holes, or have a heavily restructured skull, they are still classified as diapsids based on their ancestry. At least 17,084 species of diapsid animals are extant: 9,159 birds, and 7,925 snakes, lizards, tuatara, turtles, and crocodiles.
Emydidae 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.
The hickatee or in Spanish tortuga blanca, also called the Central American river turtle, is the only living species in the family Dermatemydidae. The species is found in the Atlantic drainages of Central America, specifically Belize, Guatemala, southern Mexico and probably Honduras. It is a relatively large-bodied species, with records of 60 cm (24 in) straight carapace length and weights of 22 kg (49 lb); although most individuals are smaller. This is a herbivorous and almost completely aquatic turtle that does not even surface to bask. Bizarrely for reptiles, the eggs can remain viable even after being underwater for weeks -in the recent past, some scientists mistakenly claimed it nests underwater, likely due to visiting Central America during a frequent flood, when nests are often submerged.
Dermochelyidae is a family of turtles which has seven extinct genera and one extant genus, including the largest living sea turtles.
The painted turtle is the most widespread native turtle of North America. It lives in slow-moving fresh waters, from southern Canada to northern Mexico, and from the Atlantic to the Pacific. The turtle is the only extant species of the genus Chrysemys, which is part of the pond turtle family Emydidae. Fossils show that the painted turtle existed 15 million years ago. Four regionally based subspecies evolved during the last ice age.
The spotted turtle, the only species of the genus Clemmys, is a small, semi-aquatic turtle that reaches a carapace length of 8–12 cm (3.1–4.7 in) upon adulthood. Their broad, smooth, low dark-colored upper shell, or carapace, ranges in its exact colour from black to a bluish black with a number of tiny yellow round spots. The spotting patterning extends from the head, to the neck and out onto the limbs. Sexually mature males have a concave plastron and a long, thick tail. By contrast, sexually mature females possess a flat plastron and have a tail notable shorter and thinner than mature males. Mature males also have a dark iris and face; females typically have a yellow or orange iris and a similarly coloured face that is distinctly lighter than males. Juveniles appear female-like in this regard and at maturity males begin to develop darker features.
Heosemys is a genus of freshwater turtles in the family Geoemydidae. The genus Heosemys was split out of the related genus Geoemyda by McDowell in 1964.
The green sea turtle, also known as the green turtle, black (sea) turtle or Pacific green turtle, is a species of large sea turtle of the family Cheloniidae. It is the only species in the genus Chelonia. Its range extends throughout tropical and subtropical seas around the world, with two distinct populations in the Atlantic and Pacific Oceans, but it is also found in the Indian Ocean. The common name refers to the usually green fat found beneath its carapace, not to the color of its carapace, which is olive to black.
The pig-nosed turtle, also known as the pitted-shelled turtle or Fly River turtle, is a species of turtle native to northern Australia and southern New Guinea. It is the only living member of the family Carettochelyidae, which are related to softshell turtles.
Box turtles are North American turtles of the genus Terrapene. Although box turtles are superficially similar to tortoises in terrestrial habits and overall appearance, they are actually members of the American pond turtle family (Emydidae). The 12 taxa which are distinguished in the genus are distributed over six species. They are largely characterized by having a domed shell which is hinged at the bottom, allowing the animal to retract its head and legs and close its shell tightly to protect itself from predators.
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.
Kinosternoidea is a superfamily of aquatic turtles, which includes two families: Dermatemydidae, and Kinosternidae.
The Madagascan big-headed turtle is a turtle native to the waters of permanent slow moving rivers and lakes in western Madagascar. These turtles are critically endangered and have been evaluated to be the most endangered turtle in the world by a 2018 review. Despite their vulnerability to extinction, they are commonly eaten for food and they are still commonly shipped from Madagascar to Asia to help meet the demand of Asia's traditional medicine market. A captive breeding program has also been started to prevent the species from becoming extinct. The Turtle Conservation Fund (TCF) intends to raise US$5.6 million to cover a five-year 'Global Action Plan' which includes captive breeding and reintroduction projects, trade monitoring, new rescue centers, local conservation plans, and educational programs.
Testudinoidea is a superfamily within the suborder Cryptodira of the order Testudines. It includes the pond turtles, Asian turtles, the monotypic big-headed turtle, and the tortoises.
The hawksbill sea turtle is a critically endangered sea turtle belonging to the family Cheloniidae. It is the only extant species in the genus Eretmochelys. The species has a worldwide distribution, with Atlantic and Indo-Pacific subspecies—E. i. imbricata and E. i. bissa, respectively.
Hoyasemys is an extinct genus of basal eucryptodiran freshwater turtle from Lower Cretaceous deposits of Cuenca Province, Spain. It is known from the holotype MCCM-LH 84, a nearly complete and articulated skeleton including the skull. It was found in the 1980s from the Las Hoyas site of the Calizas de La Huérguina Formation, near La Cierva township, Spain. It was first named by Adán Pérez-García, Marcelo S. de la Fuente and Francisco Ortega in 2011 and the type species is Hoyasemys jimenezi. The generic name is derived from the word Hoyas meaning "the basin" in Spanish, which refers to the Las Hoyas fossil site it was found in, and emys. The specific name honors Dr. Emiliano Jiménez Fuentes.
