Sea Turtles / COrrection / Plesiosaurs / Darren

[bz050@freenet.carleton.ca (Ben S. Roesch)]

Ronald Orenstein wrote:

>    How about sea turtles?  They certainly are pectoral-flipper swimmers
- do
>    they swallow stones?
I'm not well versed on sea turtles, so I'm not sure (and I'm on vacation
right now and have no access to any of my books/files). However, perhaps its
shell is enough ballast that they do not need to add any additional weight.
When I get back home (Toronto) I'm goign to look into all of this better,
and I'll post any findings I get on the list.

The correction: R. McNeill Alexander's book that I talked about is called
_Exploring Biomechanics_.

Then, Dan Varner wrote:

>    Since plesiosaurs were certainly not vegetarians with enormous guts
full of 
>    stuff to be processed, I would imagine that the gastroliths may have
>    functioned as a type of ballast, although they have been quite
rounded by
>    action in the digestive tract. 
Actually, why couldn't they been used to help digest? Did plesiosaurs feed
on shelled creatures like molluscs (or even custaceans), whose digestion
could have been aided by stones acting as grinders? I was under the
impression that plesiosaurs stuck to squid and fishes tho'

In any case, I think that the stomach of a creature that frequently ate
shelled organisms would have adapted to such a  diet, and had strong
digestive acids and enzymes. 

Dan Varner continues:

>Of course, if Darren Naish was still here there would be a very
>    authoritive 3 or 4 page answer for you. Hope he comes back soon.
That he would, and I also hope he's back soon. He's a good friend and
colleague of mine, and I just can't bare the idea of having to use
snail-mail to keep in touch (and phone costs are asking for bankruptcy)!
Darren's been offered a PhD (I hope I didn't let the cat out of the basket,
but I suppose most people here knew that) and of course he just finished a
BSc (hence no more email)...Knowing Darren though, he'll be back!

lates

ben...