Bristly Headgear: A Newly Described Dome-Headed Dinosaur Species.

A newly described species of pachycephalosaur, Platytholus clemensi, dating from around 68 million years ago, had a dome-shaped skull that was likely covered with bristles of keratin, according to paleontologists Mark Goodwin of UC Berkeley and John "Jack" Horner of Chapman University. The skull had a nasty gouge at the apex that had healed, indicating that a serious accident once befell the creature, but that it had survived long enough for new bone tissue to grow into the gash. The paleontologists classified the animal as a new genus and species, Platytholus clemensi.