Re: grass

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

Anthony Docimo writes: 

> > Their pointed beaks tend to suggest otherwise (unless there was bamboo 
> > around). If you tried to graze with a pointy beak, you'd end up eating 
> > more dirt than grass.
>
> only if the grass was as short as some people keep their lawns....on the 
> other hand, tall grass would easily be within reach.

The pointed beaks and enormous jaw muscles of ceratopians would seem to be 
overkill for eating grass - unless they were designed more for personal 
defense than food consumption. Overall though, ceratopian mouths seem better 
designed from snipping off tough vegetation (or the occasional theropod arm 
or shin). 

The basic ceratopian jaw mechanics didn't seem to change much from 
Protoceratops onwards (except for becoming bigger and more powerful). I'm 
not sure when the supposed grass phytoliths dated to, but unless grasses (in 
some form or another) were around since Protoceratops, then I doubt that 
ceratopian feeding behaviours changed all that radically. If they were to 
become specialist grazers later on, I'd expect radical changes in the shape 
of the beak (compare the muzzle shapes of mainly-browsing black rhinos to 
mainly-grazing white rhinos). 

Of course, since only phytoliths are known, then no-one really knows what 
these supposed Mesozoic grasses looked like. If they were more like bamboo 
than modern lawns then ceratopian jaw mechanics may have been well suited to 
exploiting them. I think there are too many 'maybes' concerning Mesozoic 
grass (if it existed at all) to be able to make any assumptions of its 
ecological role. 

___________________________________________________________________ 

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