Description

Late Cretaceous (Maastrichtian)
Hell Creek Formation
Powder River County, Montana, USA

Fine 2mm P4

Mammal, Multituberculate.

Mesodma was a member of Order Multituberculata, a branch of Jurassic-Eocene mammals entirely separate from any mammal groups that live today.  They would have resembled rodents and probably had much the same lifestyle but they had a different dentition.  Mesodma was one of the genera that survived into the Early Paleocene.