Gators in Colorado: Mandrasuchus milleri

Publication Info:

Transcript:

Emily J. Lessner et al. New alligatorid, Mandrasuchus milleri, from the Early Paleocene (Danian) of the Denver Basin supports earliest Paleocene North American alligatorid radiation. Journal of Vertebrate Paleontology, published online September 2, 2026; doi: 10.1080/02724634.2026.2712566

Meet Mandrasuchus milleri, the newly named alligatorid from the Denver basin immediately following the end Cretaceous mass extinction event that wiped out the dinosaurs 🦕🦖65.4 million years ago most of the life on our planet was still struggling, but this alligator relative may have been thriving!

Episode 344

Notes:

So, it's really starting to look like the only thing that stops crocs and gators from thriving is us. 66 million years ago, pretty much all life on planet had a really bad day that became a really bad month and then really bad year, really bad decade, century, millennia. You get it. Even though the impacts of space Everest getting dropped on our planet were felt all over the globe, the Americas were hit particularly hard, literally, because that's where it landed. It was bad. It was really bad for everyone. Some animals did a little bit better than others. That's why we're here. And by we, I mean everything still alive today. But, nothing had a particularly easy time. That said, according to some new research in Colorado, which is relatively close to where the Chicxulub impactor hit, only like a quarter million years later, specifically 200,000 to like 350,000, alligator relatives were already kind of thriving. Meet Mandrasuchus millerii, the 5-6 foot alligatorid from the early Paleocene Denver Basin. Now, realize I said alligatorid, it's not a true alligator, but it is on the alligator line of crocodilians. The earliest alligatoroids, which is the group even broader than alligatorids, first showed up in the Cretaceous, and they have these shorter, broader skulls than their relatives and crushing teeth. And along with some burrowing species, those are all features that are still present in Mandrasuchus 65 and a half million years ago. With its ability to take on larger prey, but also crush shells and potentially burrow, Mandrasuchus was a good generalist predator. And it makes sense that that's what would really thrive immediately following the end Cretaceous mass extinction. It also shared its ecosystem with animals like Borealosuchus and Champsosaurus, meaning that there was a lot of competition. So, it kind of makes sense that these alligatorids evolved and diversified so quickly. As usual, if you want more information, here's the source.