Too Many Teeth: Dongoconodon platycauda

Publication Info:

Transcript:

S. Bi et al. 2026. A polyphyodont, semiaquatic eutriconodontan mammal from the Early Cretaceous of China. Nat Commun 17, 10032; doi: 10.1038/s41467-026-77339-w

Meet Dongoconodon platycauda!
The 120 million years ago old Eutriconodont mammal that lived alongside the dinosaurs in Cretaceous China. This bizarre mammal is being compared to everyone's favorite bird-faced monotreme, the Platypus!

Episode 355

Notes:

How many sets of teeth do you think a mammal should have? Like even if it's a weird kind of uh weirder version of a platypus. Anyway, let's talk about it. This is Dongoconodon platycauda. 115 to 119 g eutriconodont. Eutriconodonts were a group of mammals that lived from the Jurassic to the very end of the Cretaceous, going extinct with the non-avian dinosaurs, living 184 to 66 million years ago. And Docodon specifically lived in northeastern China about 120 million years ago. And it was weird. Thanks to CT scanning, researchers know exactly how weird it was cuz first of all, unlike most mammals who just have the two sets of teeth, your baby teeth and your adult teeth, uh it had at least a third. It also had flattened, elongated hand bones similar to platypuses platypi plata platypuses. There, I double-checked it this time. It also had flanges on its long, flat fingers consistent with webbing. So, it had webbed fingers. It also had a flat tail, meaning that the comparisons to platypuses just keep on coming. And that's not really all that surprising because eutriconodonts had their own versions of a lot of what we'd consider much more normal mammals. Whether it's platypuses, cats, opossums, flying squirrels, all living throughout Asia, Africa, Europe, and the Americas. So, in the greater scheme of things, a non-monitoring platypus being a member of the eutriconodonts isn't really all that surprising. It just traded in the duckbill for an extra set of teeth. As usual, if you want more information, here's the source.