Tiny 75-million-year-old mammal offers clues on how mammals outlived the dinosaurs
UW researchers describe Cimolodon desosai, a hamster-sized Late Cretaceous mammal from Baja California, as a new species of multituberculate. Its small size, omnivorous diet and arboreal habits likely helped its lineage survive the dinosaur extinction about 66 million years ago, contributing to later mammal diversity. The fossil includes a skull, jaws and limb bones and was analyzed with micro-CT imaging to confirm its distinct status, with the name honoring field assistant Michael de Sosa VI.