Apatosaurus

deceptive lizard

• apatē (apate) · Greek · deception, deceit
• sauros · Greek · lizard

The name means "deceptive lizard". Othniel Charles Marsh chose it because the chevron bones under the tail vertebrae looked similar to those of the mosasaur-like reptiles, which could mislead researchers about what kind of animal it was.

Named by

Marsh

Year named

1877

Period

Late Jurassic

Stages

Kimmeridgian – Tithonian

Found in

Morrison Formation, western USA (Colorado, Oklahoma, Utah, Wyoming)

A diplodocid sauropod. Brontosaurus (Marsh, 1879) was long considered a junior synonym of Apatosaurus, though a 2015 study argued it is a distinct genus. The type species is Apatosaurus ajax.