During which geological epochs did *Gastornis* dominate terrestrial environments?

Answer

Paleocene and Eocene

Fossils of *Gastornis* date back to the Paleogene period, specifically spanning the early Paleocene and Eocene epochs, immediately following the extinction of the non-avian dinosaurs.

During which geological epochs did *Gastornis* dominate terrestrial environments?
fossilCenozoicbirdpaleontologyextinct