Amphicoelias

"hollow on both sides"

• amphi · Greek · on both sides
• koilos · Greek · hollow

The name combines the Greek words for "on both sides" and "hollow". Edward Drinker Cope chose it because the vertebrae are concave (amphicoelous) at both the front and back ends. Compared with the vertebrae of related sauropods, the centra are described as hollowed on both sides.

Named by

Cope

Year named

1877

Period

Late Jurassic

Stages

Kimmeridgian – Tithonian

Found in

Morrison Formation, Colorado, USA

A diplodocid sauropod. The type species is A. altus. The related species A. fragillimus, known from a very large vertebra that was later lost, was estimated to be enormous. It is now often placed in its own genus, Maraapunisaurus, though this is debated, and the original material no longer exists.