What is the smallest species of sea turtle?

The smallest species of sea turtle is the Kemp's ridley sea turtle. Also called the Atlantic ridley, it is the smallest of the world's living sea turtles and one of the rarest.

Adult Kemp's ridleys typically measure about 58–75 centimetres in carapace length and can weigh up to roughly 50 kilograms. Their shell is nearly round compared with the more elongated shells of several other sea turtles. Adults usually have an olive-gray carapace and a pale yellow-green or white underside.

This turtle is unusual because it commonly nests during the daytime. Large groups may come ashore in synchronized nesting events called arribadas, a Spanish word meaning “arrivals.” The species nests primarily along the Gulf Coast of Mexico, with an important nesting beach at Rancho Nuevo, and also uses parts of the Texas coast.

Kemp's ridley is critically endangered, largely because of historical egg collection, accidental capture in fishing gear, coastal development, and pollution. It is often confused with the olive ridley, which belongs to the same genus but is a different, generally larger species.