Poposaurus is a genus of archosaur from the Late Triassic of the southwestern United States. Like theropod dinosaurs, Poposaurus was a biped. It is theorized that it evolved this form of locomotion independently from dinosaurs and their ancestors.

In The Land Before Time

A Poposaurus briefly appears in The Land Before Time. It is seen running away from Littlefoot's egg when it falls down nearby it, along with a Lagosuchus, a Marasuchus, and a Euparkeria.