Re: Drinker and Oryctodromeus (was Re: Dinosaurs burrowed to keep warm)

[Dann Pigdon <dannj@alphalink.com.au>]

Tim Williams writes:
> If burrowing is primitive for ornithopods, then it would make sense for 
> this behavior to be retained in critters like _Atlascopcosaurus_ and 
> _Leallynasaura_, which had to endure those long polar winters in SE 
> Australia.

Although that would depend on how close to the surface permafrost was. 

Psittacosaurs may also be good burrowing candidates. A spiny tail would also 
present an unappealing target for a predator trying to drag one out of a 
burrow backwards (much like spiny-tailed lizards use their tails). 


> > Those 'eyelid bones' above the eyes would also have provided good 
> > protection from collapsing burrow material (or just plain bumping their 
> > head on the ceiling).
>
> Hey maybe that's why the pachycephalosaurs evolved really thick skulls!  
> After all, there is evidence that heterodontosaurids are closely related 
> to pachycephalosaurs.  Those thick skull roofs served as 'hard hats'!  ;-)

Come to think of it, tyrannosaurs had all sorts of hornlets and rugosities 
on top of their heads too. The forelimbs however would suggest that their 
burrowing abilities were somewhat limited... :) 

___________________________________________________________________ 

Dann Pigdon
GIS / Archaeologist         http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://heretichides.soffiles.com
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