Re: R: Giant carnivorous geese

["Steve Brusatte" <dinoland@lycos.com>]

On Sat, 24 Aug 2002 18:51:32  
 calzola wrote:

>> I'd thought the function of gastroliths was to grind up plant materials
>> while a slow process of leaching out nutrients continued.  The food was
>not
>> very nutritious.
>> What use would a carnivore have for this process?  Any excreta evidence?
>> The only reason that comes to mind is processing bone.
>> Thanks.

>I've heard (TV documentaries, nothing more..) crocs use grastroliths to help
>processing some hard tissues...

Well, gastroliths certainly do help grind up plant material, and, AFAIK, this 
is all we know them to be useful for in extant animals.  However, that 
certainly does not mean that gastroliths could not have aided carnivorous 
animals.  Actually, in many cases, they could have offered an advantage.  The 
crushing of bone, skin, tough muscle, other hard tissues, etc. are certainly 
possibilities, although it is difficult to prove (although very 
testable...sounds like a good project!).

Some carnivorous dinosaurs have been found to possess them, as have some 
probable omnivores (ornithomimosaurs).  

I don't know of any living carnivorous animals that utilize gastroliths, but it 
wouldn't surprise me if some did.  Any slight advantage posed by gastroliths 
would have made evolving the behavior of using them attractive in dinosaurs 
(and other animals), and certainly there might be use for them in carnivores, 
especially in theropod dinosaurs, which likely possessed a gizard anyway.

Steve

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