← Rex's Notes

Triceratops

Three horns, one giant frill, no patience.

Said: try-SAIR-uh-tops

Era: Cretaceous · 68 to 66 million years ago

Diet: Herbivore

Habitat: Open woodlands of western North America

Size: about the length of two cars parked end to end.

What it was like

A Triceratops skull could be over two meters long, almost as tall as a grown-up. Its frill might have flushed bright colors when it was excited or angry, like a mood ring made of bone.

What we know now

There is an ongoing debate over whether Torosaurus is a mature growth stage of Triceratops rather than a separate genus; the skull-frill morphology shifts dramatically with age. Wear patterns on the beak suggest a diet of tough, fibrous palms and cycads. Healed bite marks from T. rex appear on multiple specimens.

Notes

1. The frill is riddled with blood vessels, hinting at thermoregulation or display rather than armor.
2. Hatchlings were the size of a housecat.
3. Its teeth grew in continuously, like a shark's.