Dakotamys is a genus of extinct mammal that lived during the Upper Cretaceous. It shared the world with dinosaurs. This small creature was a member of the also extinct order Multituberculata within the suborder Cimolodonta and was a member of the Paracimexomys group. The genus Dakotamys ("Dakota mouse") was named by Eaton J.G. in 1995. Dakota refers to the Dakota Formation. It's a geological term rather than a geographical one. "Paracimexomys and Dakotamys...