Camarasaurus

Camarasaurus was a genus of quadrupedal, herbivorous dinosaurs. It was the most common of the giant sauropods to be found in North America. Its fossil remains have been found in the Morrison Formation of Colorado and Utah, dating to the late Jurassic Period, between 155 and 145 million years ago.

The name means "chambered lizard", referring to the hollow chambers in its vertebrae.