Purussaurus is an extinct genus of giant caiman that lived in South America during the Miocene epoch, from the Friasian to the Huayquerian in the SALMA classification.

[3] The large size and estimated strength of this animal appears to have allowed it to include a wide range of prey in its diet, making it an apex predator in its ecosystem.

The constantly changing environment on a large geological scale may have reduced its long-term survival, favoring smaller species more resilient to ecological shifts.

One study also indicates that Purussaurus may have been heavier than either Sarcosuchus or Deinosuchus, as it had a much broader, shorter snout and this would require a thicker, stronger neck to support the larger head.

[citation needed] Analysis of a biomechanical model of the skull of Purussaurus indicated that it was capable of performing the "death roll" maneuver used by extant crocodilians to subdue and dismember their prey.

[6] All sense organs (eyes, ears, nostrils) were at the very top of the head, indicating that Purussaurus was an ambush predator like many modern caimans.

The earlier Colombian P. neivensis lived alongside a massive variety of fauna, including astrapotheres like Granastrapotherium and Xenastrapotherium, the early species of Mourasuchus and Gryposuchus, and the terrestrial crocodyliform Langstonia.