<P> Anatomically, a few characteristics distinguish the green turtle from the other members of its family . Unlike the closely related hawksbill turtle, the green turtle's snout is very short and its beak is unhooked . The neck cannot be pulled into the shell . The sheath of the turtle's upper jaw possesses a denticulated edge, while its lower jaw has stronger, serrated, more defined denticulation . The dorsal surface of the turtle's head has a single pair of prefrontal scales . Its carapace is composed of five central scutes flanked by four pairs of lateral scutes . Underneath, the green turtle has four pairs of inframarginal scutes covering the area between the turtle's plastron and its shell . Mature C. mydas front appendages have only a single claw (as opposed to the hawksbill's two), although a second claw is sometimes prominent in young specimens . </P> <P> The carapace of the turtle has various color patterns that change over time . Hatchlings of Chelonia mydas, like those of other marine turtles, have mostly black carapaces and light - colored plastrons . Carapaces of juveniles turn dark brown to olive, while those of mature adults are either entirely brown, spotted or marbled with variegated rays . Underneath, the turtle's plastron is hued yellow . C. mydas limbs are dark - colored and lined with yellow, and are usually marked with a large dark brown spot in the center of each appendage . </P> <P> The range of the green sea turtle extends throughout tropical and subtropical oceans worldwide . The two major subpopulations are the Atlantic and the eastern Pacific subpopulations . Each population is genetically distinct, with its own set of nesting and feeding grounds within the population's known range . One of the genetic differences between the two subpopulations is the type of mitochondrial DNA found in individual's cells . Individuals from rookeries in the Atlantic Ocean and Mediterranean Sea have a similar type of mitochondrial DNA, and individuals from The Pacific and Atlantic Oceans have another type of Mitochondrial DNA . Their native range includes tropical to subtropical waters along continental coasts and islands between 30 ° N and 30 ° S. Since green sea turtles are a migrating species, their global distribution spans into the open ocean . The differences in mitochondrial DNA more than likely stems from the populations being isolated from each other by the southern tips of both South America and Africa with no warm waters for the green sea turtles to migrate through . The green sea turtle is estimated to inhabit coastal areas of more than 140 countries, with nesting sites in over 80 countries worldwide throughout the year . In the United States Atlantic coast, green sea turtles can be found from Texas and north to Massachusetts . In the United States Pacific coast, they have been found from southern California north to the southernmost tip of Alaska . The largest populations of green sea turtles within the United States coastline are in the Hawaiian Islands and Florida . Globally, the largest populations of sea turtles are in the Great Barrier Reef in Australia and the Caribbean islands . </P> <P> The green sea turtle can generally be found throughout the Atlantic Ocean . Although the species is most abundant in tropical climates, individuals have been spotted as far north as Canada in the western Atlantic, and the British Isles in the east . The subpopulation's southern range is known until past the southern tip of Africa in the east and Argentina in the western Atlantic . The major nesting sites can be found on various islands in the Caribbean, along the eastern shores of the continental United States, the eastern coast of the South American continent and most notably, on isolated North Atlantic islands . </P>

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