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Re: Sauropod gastroliths



Oliver Wings has published many articles on gastroliths from his PhD thesis.. 
Most (if not all) of these are available freely online. You found his Proc B 
article (previous link), that specifically discussed dinosaur gastroliths, but 
I suggest the following review may be of interest:


A review of gastrolith function with implications for fossil vertebrates and a 
revised classification
Oliver Wings
Acta Palaeontologica Polonica 52 (1), 2007: 1-16
Freely available at:
http://www.app.pan.pl/article/item/app52-001.html


Abstract
Misleading
interpretations of âgastrolithsâ in fossil taxa have complicated the
use of this term in palaeontology. This paper reviews the definitions
and ascribed functions of gastroliths. According to the suggested
definition, gastroliths are hard objects within the digestive tract of
animalsâwithout specification of the mechanisms that are responsible
for their accumulation. To further improve definitions, the
originâbased terms âbioâgastrolithâ, âpathoâgastrolithâ, and
âgeoâgastrolithâ are introduced. The term âexolithâ is introduced for
isolated clasts with a possible history as geoâgastroliths. Hypotheses
about the function of stomach stones in fossil and extant taxa are
reviewed, discussed and supplemented with new research. Trituration and
mixing of foodstuff are the generally accepted functions of gastroliths
in many vertebrates, including birds. In contrast, ballast provided by
swallowed stones is considered to be of limited importance for buoyancy
in aquatic animals. Other functional hypotheses include mineral supply
and storage, stomach cleaning, maintenance of a beneficial microbial
gut flora, destruction of parasites and alleviation of hunger.
Accidental ingestion of sediment, either by being mistaken for prey, by
being attached to it, during playing or due to pathological behaviour,
is considered to be common. Different functions may overlap in various
taxa.


----------------------------------
Denver Fowler
df9465@yahoo.co.uk
http://www.denverf
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----- Original Message ----
From: Ashley Fragomeni <afragome@nhm.org>
To: DML <dinosaur@usc.edu>
Sent: Tue, 1 December, 2009 12:30:18
Subject: Sauropod gastroliths

Good morning, all! 


I was reading Robert Bakker's "Dinosaur Heresies" today and am curious
about the Sauropod gastrolith issue.
Bakker, as well as many other Paleontologists, theorize that the giant
megaton Sauropods purposely ate stones to help aid in the digestion of
tough plants. 
However, I stumbled across this article online from 2007:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2197205/

What is the most accepted theory today about Sauropods and the use of
gastroliths? 



Ashley Fragomeni
Natural History Museum of Los Angeles County
Los Angeles, CA 90007