Meiolaniidae

Meiolaniidae is an extinct family of large, possibly herbivorous turtles with heavily armored heads and tails known from South America and most of Oceania. They are best known from the last surviving genus, Meiolania, which lived in the rain forests of Australia from the Miocene until the Pleistocene, and relict populations that lived on Lord Howe Island and New Caledonia until 2000 years ago. A similar form is also known from the Miocene Saint Bathans Fauna of New Zealand.

The family was once thought to have originated in Australia sometime in the Miocene, when the earliest Meiolania first appeared. However, due to the discovery of South American meiolaniids, including Crossochelys and Niolamia in Eocene Argentina, it is now believed that the meiolaniids appeared sometime prior to the breakup of Gondwana during the Cretaceous. Though once believed to be cryptodires, meiolaniids are outside of the Testudines crown-group, potentially indicating that their origin is even further back. Several basal non-testudine turtles possibly related to meiolaniids are known in both Laurasian and Gondwanan landmasses in the Cretaceous, such as the Asian Mongolochelys.

More recently, Eocene Australian species have also been uncovered.