Molluscivory take two and a few other things

[Renato Santos <dracontes@hotmail.com>]

I think from the answers I got to my question whether actual fossil evidence 
preserves molluscivory  Phil Bigelow with his:

"A taphonomic study of predation damage on large Mesozoic freshwater
mollusk shells would make a great masters thesis."

hit the nail in the head. Yes, I want to know if there are studies of such 
fossil bivalve populations and any record of land vertebrate predation on 
these. Or if anyone could get onto that study right this minute ;-) and of 
course correlate this with predation damage on extant populations of 
bivalves. I would find more interesting to know that in fact such predation 
existed than to look at a strange set of jaws and figure out what they do.
Not that I didn't find any of the other answers interesting...

To that objection of finding crushed shell in sauropod coproliths I remember 
that finely crushed hadrosaur bone was found in a coprolith attributed to 
Tyrannosaurus and being stomach acids generaly stronger in carnivores...

On another note it would be interesting, if any paleosol is available from 
the Cretaceous, to find  stones surrounded by broken shells of snails. Maybe 
some theropod was clever enough to use them as anvils as thrushes do (was 
that a pleonasm?).

On that shell-oppening method, given the unability of maniraptors and 
coelurosaurs in general to pronate their hands extensively I would argue 
that an oviraptorosaur would deftly pick up the excavated clam or mussel 
hold it between its second phalanx and metacarpal and then introduce the 
thumb claw inbetween the valves of the mollusk and cut the aductor muscles 
of its prey. Is this method too elaborate or unfeasible? I can imagine the 
antics a juvenile dinosaur would get into trying to learn this ;-D

I find it pretty interesting that they find unionid mussels in the Morrison 
Formation. During my Ecology classes I learned that extant unionids are 
indicators of healthy riverine systems with clear water and abundant 
populations of fish as these are needed for the unionid larvae's 
development. Though I know it's dificult to ascertain where this dependance 
of fish gills for these mussel's reproduction appeared.

Renato Santos

My online art gallery:
http://dracontes.deviantart.com
Comments and critics are appreciated.

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