| Florida Box Turtle Terrapene carolina | | | Chelonia mydas in Kona, Hawaii. | A turtle with eyes closer to the end of the head. Keeping only the nostrils and the eyes above the water surface. | 1. | Snapping Turtle Tail. Blue Hills Reservation, Massachusetts | "Chelonia" (Testudines) from Ernst Haeckel's Kunstformen der Natur, 1904 | The Western Hermann's Tortoise (Testudo hermanni hermanni) is a cryptodire.Cryptodires hide their head inwards. | The Western Hermann's Tortoise (Testudo hermanni hermanni) is a cryptodire.Cryptodires hide their head inwards. |
Turtles are reptiles of the order Testudines (the crown group of the superorder Chelonia), characterised by a special bony or cartilaginous shell developed …show more content…
This has inspired genetic researchers to begin examining the turtle genome for longevity genes.[7][edit] Systematics and evolutionThe first proto-turtles are believed to have existed in the early Triassic Period of the Mesozoic era, about 220 million years ago, and their shell, which has remained a remarkably stable body plan, is thought to have evolved from bony extensions of their backbones and broad ribs that expanded and grew together to form a complete shell that offered protection at every stage of its evolution, even when the bony component of the shell was not complete. This is supported by fossils of the freshwater Odontochelys semitestacea or "half-shelled turtle with teeth", from the late Triassic, which have been found near Guangling in south-west China. Odontochelys displays a complete bony plastron and an incomplete carapace, similar to an early stage of turtle embryonic development.[8] Prior to this discovery, the earliest-known fossil turtles were terrestrial and had a complete shell, offering no clue to the evolution of this remarkable anatomical feature. By the late Jurassic, turtles had …show more content…
vacuumed up entire species from areas in Southeast Asia", even as biologists still didn't know how many distinct turtle species live in the region.[31] It has been estimated that about 75% of Asia's 90 tortoise and freshwater turtle species have become threatened.[29]Harvesting wild turtles is legal in a number of states in the USA.[29] In one of these states, Florida, just a single seafood company in Fort Lauderdale was reported (2008) as buying about 5,000 pounds of softshell turtles a week. The harvesters (hunters) are paid about $2 a pound; some manage to catch as many as 30-40 turtles (500 pounds) on a good day. Some of the catch gets to the local restaurants, while most of it is exported to the Far East; Florida Fish and Wildlife Conservation Commission estimated in 2008 that around 3,000 pounds of