Oligocene turtles

Meiolaniidae is an extinct family of large, probably herbivorous stem-group turtles with heavily armored heads and clubbed tails known from South America and Australasia. Though once believed to be cryptodires, they are not closely related to any living species of turtle, and lie outside crown group Testudines, having diverged from them around or prior to the Middle Jurassic. They are best known from the last surviving genus, Meiolania, which lived in Australia from the Miocene until the Pleistocene, and insular species that lived on Lord Howe Island and New Caledonia during the Pleistocene an

Anosteira is an extinct genus of carettochelyid turtle from the Eocene to the Oligocene of Asia and North America.

Warkalania is an extinct genus of Australian meiolaniid turtle from the Oligocene or early Miocene of Riversleigh, Queensland. While other meiolaniids are known for their elaborate headcrests or long horns, Warkalania only possesses very short horns that form a somewhat continuous ridge across the back of the head. The only known species of this genus, Warkalania carinaminor, is the oldest named meiolaniid turtle of Australia.

Psephophorus is an extinct genus of sea turtle that lived from the Oligocene to the Pliocene. Its remains have been found in Europe, Africa, North America, and New Zealand. It was first named by Hermann von Meyer in 1847, and contains eight species, P. polygonus, P. calvertensis, P. eocaenus, P. oregonesis, P. californiensis, P. rupeliensis, P. scaldii, and P. terrypratchetti.