|Life reconstruction of Acrotholus audeti by Christopher DiPiazza|
Acrotholus is only known from skull chunks from a few individuals, specifically the domed tops of their heads which are two inches thick. Small dinosaurs tend not to fossilize as often as large ones because their bones are more fragile. Since the skulls of these Acrotholus were so thick, however, they managed to preserve to be discovered by paleontologists millions of years later after they died.
|One of the skull fragments from Acrotholus that was discovered. This would have been the top of the animal's head. Check out how thick it is!|
Acrotholus is amongst the oldest known pachycephalosaurids and is THE oldest known pachycephalosaurid native to North America. Even though it is more basal than all the other pachycephalosaurids that lived after it, it's head is still well-developed and thick for its size. This tells us that this adaptation, which is common in varying forms throughout the family, probably evolved much earlier than the time of Acrotholus.
That's all for this week! As always feel free to comment below or on our facebook page. If there is a dinosaur or other prehistoric creature you want to see reviewed and illustrated let me know!
Evans, D. C.; Schott, R. K.; Larson, D. W.; Brown, C. M.; Ryan, M. J. (2013). "The oldest North American pachycephalosaurid and the hidden diversity of small-bodied ornithischian dinosaurs". Nature Communications 4: 1828. doi:10.1038/ncomms2749
"Cleveland Museum of Natural History." Acrotholus Audeti. N.p., n.d. Web.