Pachycephalosaur Head Butting is a Well Rumored Theory
Pachycephalosaurus. A thick-skulled dinosaur with a head shaped like a dome. Could the purpose of such a dome be to butt heads with an opponent? Bighorn sheep indulge in such behavior nowadays, but did these dinosaurs ever do so? This question may seem trivial, but it has been the subject of divided opinion. Some scientists believe that these pachycephalosaurs were capable of bashing each other’s skulls, while other palaeontologists differ since they believe the dome-shaped heads would not stand up as good weapons in a fight.
Evidence for Pachycephalosaur Head Butting is Scant
This ambiguity is evident from bone histological study and estimations of pachycephalosaur defense ability. What is, however, clear is that there seems to be a lack of skull pathologies, which means that the ‘butting head’ theory is unlikely. An alternative explanation is that these dinosaurs rammed into their opponents’ flanks, or that the dome-shaped skull shape merely acted as an embellishment. If pachycephalosaur head butting was the norm, one should be seeing many skulls with evidence of impact caused by butting.
A Recent Study Reveals Potential Pachycephalosaur Head Butting Evidence
Such evidence of injuries pachycephalosaur head butting remained elusive for several years, but finally emerged recently with a publication by J. Peterson and C. Vittore. In a research paper entitled ‘Cranial pathologies in a specimen of Pachycephalosaurus’, published in’ PLoS One’, the authors examine a portion of a skull from one of the largest and best-known dome-heads, and find it to be damaged. It looks as though someone has bashed it with a hammer. The top of the dome shows two large depressions, and many smaller pits line the margins and inside area of these hollows.
The authors’ attempts to explain this phenomenon includes damage sustained by the skull after the animal died, resorption of bone, and a traumatic experience during the life of the individual dinosaur. However, an injury to the skull, followed by an infection of the area, is the most likely explanation that fits the evidence. It also turns out that this skull may not be one of a kind. Peterson and Vittore mention a skull from Gravitholus and one from Texacephale (both pachycephalosaurs) that show similar-looking damage to the upper surface of each.
No One Can Prove This Behavior Without a Doubt
Tempting as it is, one has to be careful to interpret such evidence – it is not definitely certain that these dome-shaped dinosaurs butted heads. One skull is not enough for basing a hypothesis on and while the injuries to the studied skull correspond with the notion that pachycephalosaurs butted heads, it is not to say that this particular specimen experienced this fate. The ‘head-butting theory’ has certainly been strengthened by this discovery, but one cannot say for sure that this did, or did not, happen as a rule.
If head-butting was a common practice in pachycephalosaurs, then more of these damaged skull fossils will exist, ready to be discovered in ancient rocks, or already waiting on museum shelves for someone to recognize as such.
Either way, it is probably safe to say that the dinosaur to which Peterson and Vittore’s studied skull belonged, must have had a whopping big headache! Researchers hope to learn more about Pachycephalosaur head butting as more specimens are examined.