Morphological Correlates of Masticatory Patterns in Peccaries and Pigs

Most of the genera of peccaries and pigs have bunodont teeth and emphasize crushing mastication. This form of mastication puts heavy vertical loading on the temporomandibular joints and is associated with relatively large condyles. The Chacoan peccary, Catagonus wagneri, and the giant forest hog, Hylochoerus meinertzhageni, have broadened, lophodont molars and emphasize grinding mastication. A mechanical analysis of grinding mastication indicates that if a posteriorly directed temporalis is the dominant muscle on the balancing side of the jaw, vertical joint loading will decrease. This finding accounts for relative small condyles in the Chacoan peccary and giant forest hog. The pattern of muscle usage is the most important determinant of condyle size.