Stegosaurus

roof lizard

• stegos · Greek · roof
• sauros · Greek · lizard

The name combines the Greek words for "roof" and "lizard". Othniel Charles Marsh chose it because he thought the animal's large bony plates lay flat along its back like roof tiles, overlapping as shingles do. We now know the plates stood upright in two staggered rows.

Named by

Marsh

Year named

1877

Period

Late Jurassic

Stages

Kimmeridgian – Tithonian

Found in

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

Valid genus. The type species is Stegosaurus armatus. Other species, such as S. stenops and S. ungulatus, have been proposed, and their validity is debated. Material from Portugal has been referred to the genus, but this is less certain.