Brontotholus

DV-1269 · type species Brontotholus harmoni

Lived: 84 to 72 million years ago, Late Cretaceous
Diet: Herbivore
Group: Pachycephalosaurs, Pachycephalosauridae
Found in: United States and Canada
Named by: Woodruff et al. 2025

Field notes

About Brontotholus

Brontotholus was a plant-eating pachycephalosaur that lived in the Late Cretaceous, 84 to 72 million years ago. It belongs to the family Pachycephalosauridae.

The Paleobiology Database lists 4 finds of Brontotholus, from Montana and Alberta. Its fossils come from rocks including the Two Medicine Formation and the Oldman Formation. It was named by Woodruff et al. in 2025.

The evidence

Where its fossils were found

Today

4 finds

80 million years ago

Map: C. R. Scotese, PALEOMAP

Lived alongside

Found in the same rock formations.

Close relatives

Other members of Pachycephalosauridae.

Sources: Paleobiology Database, WikidataNamed in: D. C. Woodruff, J. R. Horner, and M. B. Goodwin, D. C. Evans. 2025. The first pachycephalosaurid from the Late Cretaceous Two Medicine Formation: effects of the Western Interior Seaway on North American pachycephalosaurid evolution. Zoological Journal of the Linnean Society 205(2):zlaf087