Jack Horner

In 1978 John R. Horner and his field crews from Princeton University discovered dinosaur nests in western Montana. A few other finds, mostly of eggshell fragments from a number of sites, established oviparity as the only known mode of reproduction. In recent years an increasing number of…

American paleontologist Jack Horner was responsible for leading the team of researchers that uncovered the first Achelousaurus skull, MOR 485, in 1987, with Sid Hofsteader credited with the skull’s discovery. The fossil lay in the uppermost 20 meters (65.6 feet) of the formation. The species was first…