Ceratosaurus

horned lizard

• keras (keratos) · Greek · horn
• sauros · Greek · lizard

The name refers to the prominent horn on the snout of this predatory theropod, above the nostrils. Marsh coined it from Greek words for "horn" and "lizard". It also had two smaller bony ridges over the eyes, but the nose horn gave the animal its name.

Named by

Marsh

Year named

1884

Period

Late Jurassic

Stages

Kimmeridgian – Tithonian

Found in

Morrison Formation, western USA (Colorado, Utah, Wyoming); possibly also Portugal (Lourinhã Formation)

Valid genus. Type species is Ceratosaurus nasicornis. It gives its name to the group Ceratosauria. Other species have been proposed, and Portuguese material has been referred to the genus.