Re: Archaeopteryx, Othnielia & pachycephalosaurs

[John Conway <john_conway@mac.com>]

On Thursday, January 16, 2003, at 08:13  AM, Steve Brusatte wrote:

> I *think* Goodwin's research showed that pachycephalosaurs likely 
> didn't butt heads straight on, as the shapes of the skulls would have 
> led to ineffective glancing blows.  He used the analogy of two bowling 
> balls hitting each other.  The bowling balls are both thick and 
> strong, but the spherical shape leads to a very small area of contact. 
>  This reduces the effectiveness of any head butt, as not only would it 
> make the butt weaker, but it would also be more unpredictable (and 
> likely more dangerous).

R. McNiell Alexander discusses the forces involved in pachycephalosaur 
head-butting in "The Complete Dinosaur" p. 422. He argues that the neck 
muscles of pachycephalosaurs could easily absorb any sideways motion 
caused by a glancing blow, so it probably wasn't dangerous.

> So, what were the thick skulls used for?  Some have said flank butting 
> (i.e., just like head butting, but instead of two heads colliding, one 
> pachy would smash its head into the flank of another, possibly a 
> rival, but who can be sure?).
>
> This is probably the best explanation, but we can never be certain.

The dome seems a bit extreme for flank butting, doesn't it? I think 
even my own noggin could withstand a bit of rib butting, and I'm only 
moderately bone-headed. :-)


John Conway, Palaeoartist

"Do I contradict myself? Very well, then I contradict myself, I am 
large, I contain multitudes." - Walt Whitman

Systematic ramblings: http://homepage.mac.com/john_conway/
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