Dinosaurs in decline long before asteroid catastrophe, study reveals

New research resolves longstanding controversy, showing dinosaurs were already heading for extinction before the asteroid strike that sealed their fate

Dinosaurs were in decline long before the asteroid struck that spelt their doom, new research suggests.

Dinosaurs were on the up and up from the late Triassic about 220m years ago, with new species arising faster than others went extinct. But the study reveals their fortunes had begun to change long before the catastrophic six-mile-wide asteroid hit what is now the Gulf of Mexico, 66m years ago.