Sauroposeidon

What it was like

Sauroposeidon was an enormous, long-necked plant eater, among the tallest dinosaurs known. Its neck was built from long, air-filled vertebrae that made it lighter than its size would suggest, while still able to reach high into the treetops.

It belonged to a group of sauropods called titanosauriforms, related to Brachiosaurus in early studies, though later research suggested closer ties to the titanosaurs instead. Exact size estimates remain uncertain because so little of the skeleton has been found.

Its world

Sauroposeidon lived in what is now Wyoming, Oklahoma, and Texas, from about 121 to 94 million years ago, spanning the Early to Late Cretaceous. Its fossils come from formations including Cloverly, Antlers, and Twin Mountains.

It shared its coastal habitat with the predator Acrocanthosaurus, the plant eater Tenontosaurus, the armored Sauropelta, and the small hunter Deinonychus.

How it was found

Wedel and colleagues named Sauroposeidon in 2000, after the huge vertebrae found were initially mistaken for petrified wood. Only 5 finds of the genus are known, making it one of the rarest large sauropods in the fossil record.