Too Many Crocs: An Ecosystem Ruled By Purussaurus

Publication Info:

Transcript:

E. Wilson et al. Physical evidence of crocodylian predation on ungulates in the Middle Miocene of Colombia. Journal of Vertebrate Paleontology, published online August 16, 2026; doi: 10.1080/02724634.2026.2701154

This may not be your first time hearing about Purussaurus, but it may be your first time hearing about how it fit into its ecosystems. Brand New research is giving paleontologists new insights into the La Venta Miocene ecosystem, ruled by the extinct giant cayman!

Episode 328

Notes:

Come and get it. >> Have you ever wondered what happens to an ecosystem with giant crocs? And I mean truly giant crocs. Animals like Purussaurus, the giant Miocene caiman from South America, the biggest species of which Braziliensis grew to 40 or maybe even 50 ft long depending on the estimate. Well, unsurprisingly predators that size can eat a lot even when they have a croc metabolism which is slower than a giant mammal. And it's definitely enough that it can either affect the ecosystem that they're in or affect the ecosystem they end up in. And the Miocene La Venta assemblage in Colombia is the perfect example. First, it has a Purussaurus, Purussaurus neivensis. It's one of the smaller species reaching only 20 to 30 ft, you know, small. Just way bigger than any modern caiman or any crocodilian a modern person will ever run into. And it also has a lot of big mammalian herbivores. And Hemitrygon, Xenastrapotherium, and Granastrapotherium. All relatively large ungulates. According to new research it looks like all they really had to worry about was Purussaurus. Cuz the ecosystem didn't have any large mammalian predators. Given Purussaurus is a big threat. And part of how they came to this conclusion was finding specimens of all of these animals with giant conical teeth marks and crushing damage to their bones. It's also worth noting that Xenastrapotherium remains were found with smaller bite marks on it that according to the researchers is consistent with Langstonia scavenging. Langstonia being a relatively smaller sebacid. This lack of terrestrial mammalian predators along with damage from Purussaurus consistent with previous biomass estimates for the ecosystem. Meaning that at least in this ecosystem the apex predators that would usually be mammalian predators were replaced by giant crocs like Purussaurus. As usual, if you want more information here's the source.