Reconstruction of Purussarus neivensis attacking Pericotoxodon platignathus. Credit: Miguel Hernandez

Fossil bite marks suggest giant crocodylians, especially Purussaurus neivensis, dominated large prey hunting in Miocene South America.

More than 10 million years ago, a vast lake spread across much of South America, surrounded by an extraordinary collection of predators and prey. Giant turtles and crocodylians occupied its waters, while anacondas, saber-toothed mammals, flightless “terror birds,” and sebecids, terrestrial relatives of crocodylians, hunted along its shores.

Among all of these predators, new research suggests that crocodylians played the dominant role in this Miocene ecosystem.

“There was so much prey available that mammalian predators couldn’t have eaten it all,” says Oscar Wilson, postdoctoral researcher at the University of Helsinki.

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

Skull of Pericotoxodon platignathus showing the puncture mark likely made by Purussaurus neivensis. Credit: University of Helsinki

Giant crocodylians dominated large prey

The lakeshore supported an equally impressive range of herbivores. Giant ground sloths, glyptodonts, which were relatives of armadillos, and several groups of ungulates lived there, including astrapotheres (“lightning beasts”) and toxodontids. Some of these ungulates could weigh well over a metric ton.

Their predators could reach enormous sizes as well. The largest known predator in the ecosystem was Purussaurus neivensis, a relative of modern caimans that grew to about seven meters long and weighed roughly 1,800 kilograms. As an apex predator, it may even have helped shape the size of local herbivore populations, according to the study.

Jawbone of Xenastrapotherium kraglievichi that features marks of both predation by Purussaruus neivensis and possible scavenging by Langstonia huilensis. Credit: University of Helsinki

Bite marks reveal the predator hierarchy

To reconstruct these ancient interactions, researchers examined fossils preserved in museum collections. Bite and tooth marks left on herbivore remains provide the only direct evidence that particular predators interacted with their prey. The fossils included in the analysis ranged from 10.5 million to 16 million years old.

“The frequency of marks likely made by Purussaurus suggests that it was an important predator in these tropical ecosystems,” Wilson comments.

Reference: “Physical evidence of crocodylian predation on ungulates in the Middle Miocene of Colombia” by Oscar E. Wilson, Jorge W. Moreno-Bernal, Catalina Suarez, Frank Cardozo Tovar, Andrés Vanegas, Rubén Vanegas, Ethan A. Shirley, Patricia A. Holroyd and John-Paul Zonneveld, 16 August 2026, Journal of Vertebrate Paleontology.
DOI: 10.1080/02724634.2026.2701154

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