The Los Angeles Times reports (http://lat.ms/1eZ7mrN) Thursday that the skull is believed to be 12 million to 15 million years old.
Life sciences teacher Martin Byhower noticed the fossil two years ago on the Chadwick School's campus on Palos Verdes Peninsula, which has ocean sediments thrust high above the Pacific by tectonic activity over millions of years.
Byhower's efforts to seek help in identifying the fossil resulted in a visit by Howell Thomas of the Natural History Museum of Los Angeles County. Howell says he quickly identified the rear of the skull, blow hole and the snout.
It may be a year before the skull is fully revealed.
Information from: Los Angeles Times, http://www.latimes.com