Ankylosaurus- The Skull

Photo by William Diller Matthew

There are three known Ankylosaurus skulls. Those three skulls are similar but have noticeable differences; the reigning idea is that the differences are taphonomic in nature rather than ontogenetic or species related. We know that Ankylosaurus has a large beak and small eyes and that the skull is covered in dense dermal bone and small crests and horns. Of particular note are the jugal horns that face ventrocaudally and give the skull a triangular appearance in lateral view. The teeth of Ankylosaurus comprised a large dental battery of up to 36 teeth per side of the mandible and 35 teeth per side in the maxilla. This may be slightly misleading as the only mandible known is from the smallest of the known specimens. There are many more aspects of the skulls that are interesting and strange, but the teeth of Ankylosaurus deserve some specific attention here. The teeth are leaf or spade shaped and mediolaterally compressed. The rostral and caudal margins are covered in serrated lobed denticles. The most caudal teeth appear to have curved caudally meaning that plant matter was processed by the teeth even up to the moment of swallowing.

Illustration by Barnum Brown