The flat-tailed sea turtle ( Pyxis planicauda ) is a turtle of the family Testudinidae endemic to Madagascar and is one of the 25 most endangered species of turtles on the planet according to an assessment carried out by the IUCN in The carapace is up to 13.4 cm long,is elongated and slightly flattened on the back.The scales around the perimeter are dark and have a yellow band.The plastron is yellow,has dark spots and does not present an anal gap. The male weighs between 300 and 400 g,and the female weighs between 475-670. It has a flat tail (from which its scientific name derives ) and that of the female is thinner and shorter than that of the male. The color of the legs,with five nails,varies from yellow to brown.The hind legs are covered by large yellow scales. The head,of medium size,varies in color from dark brown to black and has yellow spots of various shapes. Its sexual dimorphism is clearly visible from 10-12 years of age.