Ancient Purussaurus Was South America's Ultimate Crocodilian Predator

Modern crocodiles rank among the most feared predators alive, yet their ancient kin make living crocs look about as menacing as a cold-stricken kitten that wants a cuddle.

From early crocodyliforms to Purussaurus neivensis

It took time to get there. Since crocodyliforms first appeared more than 200 million years ago, they have passed through relatively harmless vegetarian phases and even evolved a genuinely cat-like body form.

Eventually, evolution produced some truly astonishing varieties that dominated their ecosystems with a scaly fist.

Meet the cold-blooded Purussaurus neivensis, an ancestor of caimans that reached 7 metres in length and weighed 1,800 kilograms, roughly as much as an average car.

First formally described in 1941 and named for the nearby Purus River, this giant has been identified in a new study in the Journal of Vertebrate Paleontology as South America's apex predator during the Miocene, 23 million to 5.3 million years ago. The conclusion comes from the battered remains of its victims.

P. neivensis taking down a victim, the mammal Pericotoxodon platignathus, in an artistic recreation of existing fossil evidence. (Wilson et al., J. Vertebr. Paleontol., 2026/artist Miguel Hernandez)

The team reconstructed the hunting methods and bone-crushing strength of these ancient crocodyliforms by examining gruesome fossils recovered from Colombia's present-day La Tatacoa Desert.

Fossil bite marks reveal Purussaurus prey

The evidence consists of four fossils dated to between 10.5 and 16 million years ago, all bearing traces of a prehistoric assault: part of a skull, a femur, and two lower jaws. They came from three different kinds of ungulate – hoofed mammals that are generally plant-eaters.

The unlucky ungulates were probably meals for P. neivensis, judging by the dimensions and form of the bite marks.

One of the four pieces of fossil evidence presented: The skull of P. platignathus with a puncture mark that appears to have been made by P. neivensis. (University of Helsinki)

These herbivorous prey animals were imposing creatures themselves, with members of their species potentially weighing far more than a tonne.

They also had formidable traits, including tree-trunk-like legs, tusks and rhino-like bodies, alongside equally hefty, Star Wars-style names such as Granastrapotherium snorki.

A reconstruction of G. snorki, one of the prey animals analysed in this study. (Rextron/Wikimedia Commons)/CC BY-SA 3.0

"The frequency of marks likely made by Purussaurus suggests that it was an important predator in these tropical ecosystems," says Oscar Wilson, a vertebrate palaeontologist at the University of Helsinki and the study's first author.

Although large placental mammal predators may dominate communities today, that was not always so.

Before the Great American Biotic Interchange – a major migration of land and sea animals between North and South America, rather like a continental Pokémon trade – other predators held prominence.

For instance, P. neivensis shared its habitat with terrifying non-mammalian hunters, including enormous madtsoiid constrictor snakes.

It also lived alongside phorusrhacid 'terror birds', whose massive beaks and towering height meant they could dunk a basketball simply by rising on the tips of their killer-clawed feet.

"There was so much prey available that mammalian predators couldn't have eaten it all," Wilson explains.

"Our new study shows that crocodylians in particular were the region's most important predators, especially when it came to hunting large prey."

Giant prey and a Miocene death roll

Evidence from living species supports crocodilians' tendency to tackle huge prey.

Saltwater crocodiles (Crocodylus porosus), the largest crocodiles alive, can reach about 1,200 kilograms. They are known to target domestic horses and bulls, as well as feral water buffalo in Australia.

Likewise, Nile crocodiles have been observed feeding on hippos and rhinos in Africa, although their ancestors may have hunted prey that was proportionally even larger, the researchers note.

Related: An Ancient Shark Graveyard Has Been Found in The Egyptian Desert

Taken together, the study tells a story of extraordinary power maintained across vast stretches of time, recreating hunting encounters absent for many millions of years.

To produce the fossil evidence examined here, P. neivensis may have seized unsuspecting victims by the head while they drank, crushing their skulls with a bite force perhaps exceeding that of Tyrannosaurus rex, then pulling them apart with the feared death roll.

In doing so, it also aided its Miocene companions by leaving scraps behind.

The aforementioned leftovers: The terrestrial crocodyliform Langstonia huilensis scavenging the carcass of Xenastrapotherium kraglievichi, whose fossil mandible (analysed in this study) shows marks consistent with scavenging, in addition to punctures likely inflicted by P. neivensis. (Wilson et al., J. Vertebr. Paleontol., 2026/artist Miguel Hernandez)

Finally, it supported aquatic ecosystems by moving nutrients from land into the water – in its faeces.

This research was published in the Journal of Vertebrate Paleontology.

This article was fact-checked by Rachel Garner and edited by Rebecca Dyer. While we take pride in our process, we are only human. If you spot an error, please let us know.