08/09/2026
Caseosaurus looked like a latecomer to the dinosaur party, but it might have been one of the very first dinosaurs in North America — and that changes everything. This small Triassic predator from Texas, once dismissed as just another fragmentary fossil, now challenges the timeline of when dinosaurs really arrived on the continent. If Caseosaurus truly was an early dinosaur (and not just a dinosauriform cousin), it means North America had its own native dinosaur lineage much earlier than scientists once thought — rewriting the story of how these animals spread across Pangea before the supercontinent even broke apart.