Triceratops skull with early mammals.

- Image ID: E1JM4W
Triceratops skull with early mammals.
Stocktrek Images, Inc. / Alamy Stock Photo
Image ID: E1JM4W
Triceratops skull with early mammals from the Late Cretaceous and Paleocene of North America. Gobiconodon (insectivore, left), Ptilodus (early gnawer, center), Eodelphis (early possum).