Rock unit

Milk River

3 dinosaur genera in Omnisaura with fossils from the Milk River, oldest first. See all rock units.

ParonychodonCope 1876
Bones100.5–66 million years ago
RichardoestesiaCurrie et al. 1990
Bones100.5–66 million years ago
AcrotholusEvans et al. 2013
Bones85.7–83.6 million years ago