Short of watching The Lost World: Jurassic Park for the umpteenth time, there’s no way to see pachycephalosaurs really butting heads like they used to, 72 million years ago. But scientists from the University of Calgary have now come closer than ever before, and they’ve shown that the head-butting practices of these ancient creatures are unparalleled even to the present day.
Stegoceras validum was a plant-eater about the size of a large dog or a goat. Like all pachycephalosaurs (from the Greek pachys for thick, and kephale for head) it sports an impressive domed skull, but until now it wasn’t perfectly clear what it was used for. Was it really a helmet designed for combat between species, or was it just decorative, like peacock’s tail?
To find out, the team used computed tomographic (CT) scans, physical sectioning, and elemental analysis to look at the internal cranial structure of both the S. validum and living head-butters like the duiker, a small-to-medium-sized antelope from sub-saharan Africa. They then used computer models and statistical analysis to compare how the skulls would have absorbed the stress of a head butt.
“Our analyses are the closest we can get to observing their behavior. In a way, we can get ‘inside their heads’ by colliding them together virtually. We combined anatomical and engineering analyses of all these animals for a pretty thorough approach,” says University of Calgary alumnus (now a post-doctoral researcher in biomedical engineering at Ohio University) Eric Snively, who co-authored the paper.
The result: Stegoceras validum skulls could definitely handle a solid head-butting, in fact, they’re probably better for protecting the brain than any living animal.
You can read the full paper in PLoS ONE, but in addition to that, the team has produced this nifty video showing the stresses that appear on the skulls of both a duikier and S. validum during a collision. The evidence is clear: pachycephalosaurs were built tough.