Histological examination reveals that pachycephalosaurid domes are composed of a unique form of fibrolamellar bone which contains fibroblasts that play a critical role in wound healing, and are capable of rapidly depositing bone during remodeling. Peterson et al. (2013) concluded that taken together, the frequency of lesion distribution and the bone structure of frontoparietal domes, lends strong support to the hypothesis that pachycephalosaurids used their unique cranial structures for agonistic behavior. CT scan comparisons of the skulls of "Stegoceras validum", "Prenocephale prenes", and several head-striking artiodactyls have also supported pachycephalosaurids as being well-equipped for head-butting.