ðĶ BEFORE DINOSAURS: THE ARCHOSAURS
PAGE 1 OF 5 — REPTILES BEFORE THE DINOSAURS
250 MA
THE RULING REPTILES
Long before T. rex, a group called archosaurs, meaning "ruling reptiles", dominated land and water. They were not dinosaurs yet, but they carried the blueprint. Archosaurs first appeared in the Early Triassic, recognisable by two clever features: an extra opening in the skull in front of the eye, and a hole in the lower jaw. From this single group, life split into two great branches: one leading to crocodiles, the other to dinosaurs and, eventually, birds.
⥠WHAT MAKES AN ARCHOSAUR?
A skull opening in front of the eye (the antorbital fenestra), teeth set in sockets, and a hole in the lower jaw. These tiny clues let scientists trace the family tree of crocodiles, dinosaurs and birds back to one ancestor.
"The ruling reptiles before the first dinosaur."
ROOTS!
CROC LINE
ð Low-slung armoured predators
ðĶī Ancestors of modern crocodiles
ðĄïļ Bony back plates called osteoderms
ðĶī Ancestors of modern crocodiles
ðĄïļ Bony back plates called osteoderms
DINO LINE
ðĶ Slender, fast bipedal runners
ðĶ Ancestors of dinosaurs and birds
ðĶĩ Legs tucked straight under the body
ðĶ Ancestors of dinosaurs and birds
ðĶĩ Legs tucked straight under the body