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

[don ohmes <d_ohmes@yahoo.com>]

Curiosity is festering, and I don't seem to have (easy) access to these papers 
(any pdf's appreciated), so I'll just have to ask; does anybody know what the 
ostriches used in the Wings' study were eating? 

Don

----- Original Message ----
From: Denver Fowler <df9465@yahoo.co.uk>
To: dinosaur@usc.edu
Sent: Saturday, December 30, 2006 6:45:10 AM
Subject: Re: Gastric stones of dinosaurs were not for milling food !



>If the big rock exhibits the characteristic sheen 

Wings' studies demonstrate unequivocally that genuine gastroliths from gastric 
mills of extant taxa do not have a 'characteristic sheen'. This is another 
'urban myth' of palaeontology.

>So... what are the surface characteristics of bona fide non-avian
gastroliths, those found within the complete torsos of dinosaur specimens
such as _Sinornithomimus_ or _Caudipteryx_?       

Wings is in the process of publishing various papers from his thesis which 
answer this and other questions, and debunk old ideas. I suppose, look out for 
more on the horizon.

Regarding seismo... I don't have a strong opinion on the subject, but there are 
undoubtedly many pebble-cobble sized stones in various layers within the 
sandstones from which the skeleton was extracted. Having visited the site, I am 
more inclined to agree with Spencer Lucas (2000) that these are 'gastromyths' 
in Seismosaurus, although I believe Oliver Wings is inclined to think at least 
some of the stones may be genuine (those found within the body cavity itself). 
The choking idea is silly though: the 4 cervical vertebrae were isolated and 
eroded (Gillette 1992), not articulated and pristine, so the fact that they 
found a large stone where the throat 'could have been', means nothing.

I could ramble on, but I'm just re-iterating Oliver's work. I would suggest 
reading some of his papers, since they cover all this in exhaustive detail, or 
the soon-to-be-published-hopefully ones will.

D.

ref: NMMNH-2000-17-Lucas-gastromyths seismosaurus, gastroliths, sauropod, LJ, 
MOR Fm, Nm, USA



So many questions.

---Ralph

Dino Guy Ralph
Docent at the California Academy of Sciences
Dinosaur and Fossil Education
Member of the Society of Vertebrate Paleontology








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