Flatback sea turtle

The Australian flatback sea turtle (Natator depressus)[4] 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 carapacelength 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.[1] It was previously listed as vulnerable in 1994.[5] It is not as threatened as other sea turtles due to its small dispersal range.[6] This animal can be 31 to 37 inches long and about 100 kg in weight

The flatback sea turtle was originally described as Chelonia depressa in 1880 by American herpetologist Samuel Garman. The genus Natator (meaning "swimmer") was created in 1908 by Australian ichthyologist Allan Riverstone McCulloch, and in the same scientific paper he described what he thought to be a new species, Natator tessellatus, thereby creating a junior synonym. In 1988 Swiss paleontologist Rainer Zangerl assigned the flatback sea turtle to the genus Natator as the new combination Natator depressus. Because Chelonia is feminine, and Natator is masculine, the specific name was changed from depressa to depressus.

The flatback turtle is a sea turtle that can be recognized by its smooth flat-domed shell, or carapace, which has upturned edges along the sides. It has the coloration of olive green or a mixture of grey and green. This matches the coloration of its head. The underside, also called the plastron, has a much lighter coloration of a pale yellow. The flatback sea turtle has an average carapace length ranging from 76 to 96 cm (30 to 38 in), and weighs from 70 to 90 kg (about 155 to 200 lb).[6] The females of this species are larger than the males in adulthood and also have been found to have longer tails than their male counterparts.[6]

Features of this sea turtle which help contribute to its recognition are the single pair of prefrontal scales on the head, and the four pairs of costal scutes on the carapace.[7] Another unique feature of this species of sea turtle is the fact that its carapace is found to be much thinner than other sea turtle carapaces.[6] This feature causes the shell to crack under the smallest pressures.[6]

The skull superficially resembles that of the olive ridley but details of the braincase most closely resemble those found in the green sea turtle[8]

Illustration of a top view of a flatback sea turtle.
A flatback turtle hatchling on its way to the sea.
A sea cucumber, which is an organism found in the flatback sea turtle's diet.
A fox, which is a terrestrial predator of the flatback sea turtle.
An example of gillnets, which are a threat to the flatback sea turtle.