Prenocelphale prenes -Maryanska et Osmolska, 1974- cast of the skull
Archosauria: Ornithischia: Pachycephalosauria: Pachycephalosauridae
Locality: Omnogov, Gobi Desert, southern Mongolia
Age: Late Cretaceous (Late Campanian-Early Maastrichtian), 74 million years ago
Meaning of the name: "sloping head"
The pachycephalosaurians, known mainly from the Late Cretaceous of the northern hemisphere, were bipedals with unusually thickened skull roof forming a dome. This dome was flat in the homalocephalids (Homalocephalae) and swelled in pachycephalosaurieds (Prenocephalae). It is supposed, the dome might serve as a combat ram for intraspecific competition, like horn in mammals. This interpretation is comformed with strengthened rigid vertebral column that could transmit effectively forces from the head to the pelvic when bumping heads.