Re: Gastric stones of dinosaurs were not for milling food !

[don ohmes <d_ohmes@yahoo.com>]

Well, if family tradition mandated I swallow a stone, I'd be picky too... just 
kidding. I think it is a good question. If the "picky" observation is valid, it 
at least takes the "incidental" hypothesis out of the equation, re crocs.

BTW-- This no criticism of the Wings' paper(s), but I still think it would be 
interesting as a next step to feed ostriches a controlled (all leaf, no grit) 
diet, as opposed to free range, and see what the effect on polish is. You can't 
tumble a rock with just anything and expect a polish.

Don

----- Original Message ----
From: Dann Pigdon <dannj@alphalink.com.au>
To: DML <dinosaur@usc.edu>
Sent: Monday, January 1, 2007 8:43:13 PM
Subject: Re: Gastric stones of dinosaurs were not for milling food !

John Scanlon writes: 

> Take-home message: no evidence for a gizzard in non-avians, and incidental
> ingestion may explain all other cases of gastroliths (including in
> crocodilians).

Surely gastroliths in living crocs are well studied? Crocs will go out of 
their way to collect stones from specific sources, sometimes well outside of 
their usual territories. 

Or does the paper suggest that croc gastroliths are purely for buoyancy 
purposes and have little to do with digestion? If so, then why are they so 
picky about the types of stones they ingest? 

___________________________________________________________________ 

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