Alaskacephale

Phylogeny: Dinosauria > Ornithischia > Genasauria > Neornithischia > Cerapoda > Marginocephalia > Pachycephalosauria > Pachycephalosauridae > Pachycephalosaurinae

Overview: Dinosaurs in the clade Marginocephalia are split into two major lineages - the Ceratopsia and the Pachycephalosauria. Alaskacephale belonged to the latter group. While later ceratopsians evolved to be quadrupedal and grew quite enormous, pachycephalosaurs generally stayed relatively small and were entirely bipedal. Both groups are famous for their unusual skull anatomy, however. Alaskacephale is a good example of a pachycephalosaur. These animals, with few exceptions, tended to possess thickened domes of bone atop their skulls, the exact purpose of which is hard to determine. One idea, often depicted in popular media, is that these dinosaurs used their domes for direct head-butting behavior, either as a defense against predators or for intraspecific competition (competing males for instance). Some evidence suggests that side-to-side strikes between individuals were more common, based on their neck anatomy. The thickened bone could also store minerals or be used in some way for heat exchange.

Alaskacephale and its relatives are generally thought to have been herbivorous, though some do speculate that pachycephalosaurs were omnivores. They usually had fairly narrow, beaked snouts with small teeth lining the jaws. Food sources included ferns, cycads, young conifers, tubers and even fruit, possibly supplemented by insects or grubs. Pachycephalosaurs tended to be low-browsers due to their size. The exact size of Alaskacephale itself is hard to determine as it’s only known from parts of the skull, which is fairly common for pachycephalosaurs. Often, their skull domes were the most solid and easily fossilized part of the body. This genus may’ve been about two or so meters long, so average-sized for its kin. Scientists place Alaskacephale within the family Pachycephalosauridae, so Pachycephalosaurus itself was a close relative. Alaskacephale is known from much farther north, in what is now the northern part of Alaska, within the rocks of the Prince Creek Formation. Earth in the Late Cretaceous was warmer than today, but Alaskacephale still had to contend with colder periods of extended darkness.