The Museum's Late Jurassic sauropod
- WhereKirtland Hall of Prehistoric Life
The Museum's Late Jurassic sauropod, known as Happy, is the only known adult specimen of this dinosaur complete enough to display in its entirety. Happy is the holotype of Haplocanthosaurus delfsi. In life, this dinosaur was probably more than 72 feet long and 14 feet tall at the hips, with a weight of about 25 tons. This plant-eater would have required a massive amount of plant material to feed itself. Nearly half the bones in this 70-foot-long, 14-foot-high mounted skeleton are actual fossil material, and the 6-foot-4-inch thigh bone is the oldest displayed anywhere in the world.