Fossils of Euparkeria, including nearly complete skeletons, have been recovered from the Cynognathus Assemblage Zone (CAZ, also known as the Burgersdorp Formation), which hosts the oldest advanced archosauriforms in the fossil-rich Karoo Basin.

It was a small carnivorous reptile with a boxy skull, slender limbs, and two rows of tiny teardrop-shaped osteoderms (bony scutes) along its backbone.

Euparkeria is a eucrocopod, meaning that it was among the reptiles most closely related to true crown group archosaurs, according to specializations of the ankle and hindlimbs.

Other possible adaptations to bipedalism in Euparkeria include rows of osteoderms that could stabilize the back and a long tail that could act as a counterbalance to the rest of the body.

[1] However, adaptations to bipedalism in Euparkeria are not as obvious as they are in some other Triassic archosauriforms such as dinosaurs and poposauroids; the forelimbs are still relatively long and the head is so large that the tail might not have effectively counterbalanced its weight.

The hindlimbs of Euparkeria have been used to argue that the evolution of a fully erect gait in true archosaurs was a stepwise process which first developed in bones closer to the hip.

Models of weight distribution found that the center of mass for Euparkeria was far in front of the hips, meaning that a body held horizontally during a bipedal stance would have to fight against a very large forward pitching moment.

During the Early Triassic the Karoo Basin was at about 65 degrees south latitude, meaning that Euparkeria would have experienced long periods of darkness in winter months.

Early phylogenetic analyses created by Jacques Gauthier in the 1980s provided an alternative hypothesis, that Euparkeria was closer to dinosaurs (including birds) rather than crocodilians.

Sterling Nesbitt's influential 2011 monograph on archosaurian relationships found a similar result, although he also placed phytosaurs as the sister group to Archosauria, rather than Euparkeria.