Pleurocoelus

hollow side (referring to hollow vertebrae)

• pleuro · Greek · side / rib
• koilos · Greek · hollow

The name combines the Greek words 'pleuro' (side or rib) and 'koilos' (hollow), referring to the prominent pleurocoels — large cavities or hollows on the sides of the vertebrae — that characterised the fossils when they were first described. Such vertebral hollows are a hallmark of sauropod dinosaurs and help reduce the weight of the backbone. Marsh chose this feature as the defining characteristic of the genus when he named it in 1888.

Named by

Marsh

Year named

1888

Period

Early Cretaceous

Stages

Aptian – Albian

Found in

Arundel Formation, Maryland, USA; also Texas, USA

Pleurocoelus is a sauropod dinosaur (titanosauriform / brachiosaurid-grade) from the Early Cretaceous of North America. It is widely regarded as a nomen dubium because the type material — fragmentary vertebrae and teeth from the Arundel Formation of Maryland — is too incomplete to confidently diagnose a distinct genus. The Texas material once referred to Pleurocoelus is now generally assigned to Sauroposeidon or left as indeterminate titanosauriforms. Pleurocoelus is nevertheless the official state dinosaur of Texas, largely for historical reasons.