Poison Creek Quarry, opened and operated by the paleontology department between 1977-1990, yielded many dinosaur specimens including at least seven kinds. Among the remains of Diplodocus was this skull of an immature individual. Other Diplodocus of various age groups were also present which suggests the presence of a herd of Diplodocus at the site some 150 million years ago during the Late Jurassic.

The small skull is a favorite because it is complete with teeth and lower jaw. Internal details of the skull and brain cavity are also known from CT scans. It’s long, bluntly-pointed snout may indicate immature development or possibly an unknown species of Diplodocus.
– Bruce R. Erickson, Fitzpatrick Chair of Paleontology