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Re: Wading sauropods



Greg Paul has written:

To: dinosaur@usc.edu
Date: Monday, July 27, 1998 3:05 AM
Subject: Wading sauropods


[...SNIP...]

>Along these lines, tooth microwear studies by Forillo
>indicate the diplodocid teeth lack the grit marks expected in animals that
fed
>low and close to soil.

[...SNIP...]

    In evaluating the  general applicability of conclusions based upon any
such study, one must ask whether the examples involved  are  really adequate
(or whether they represent only  a highly limited and all-too-localized
sampling) to become a basis for the seemingly generalized conclusions to
which you are applying them.  After all, just how many deplodocid heads (and
teeth) have been found, worldwide?


    I have not seen the study you mention, and you have provided only a last
name of the author -- no paper title, no publication name, not even a date.
How many diplodocid tooth samples (how many  diplodocids' provided the tooth
samples)?  Also, did the paper's AUTHOR make the generalized conclusion you
seem to be presenting, or they soley your own?

    You further said:


>Feeding on deep plants can be ruled out simply because
>there is not enough light below a few feet in most bodies of freshwater to
>sustain growth.  [END OF QUOTE.]

    Not so (feeding on deep plants cannot be ruled out because...), and I
find it hard to believe that this conclusion is based upon upon a careful
evaluation of the kind of paleo-environment(s) within which sauropod tracks
have been found.

    Keep in mind that at least most, and possibly all, the Texas sauropod
tracks are in carbonate (marine sedimentary) substrates. One is looking at
what were MARINE sediments -- sometimes those of placid marine lagoons.
These aquatic environments often have marvelously, beautifully CLEAR waters.
Likewise for those found at the Briar quarry in Arkanses. [Reference:
Brontopodus Birdi, Lower Cretaceous Sauropod Footprints from the U.S. Gulf
Coastal Plain, James O. Farolw, Jeffrey Pittman, and J. Michael Hawthorne,
published in DINOSAUR TRACKS AND TRACES, Gillllette and Lockley (Editors),
Cambridge University Press, 1989.  Other, related papers are found in this
important book.].  If anyone is interested I could provide several other
sauropod track-site references to widely located areas (off list, please).

    I should also mention that even fresh-water ponds and lakes with bottoms
of carbonate sedimentary material can be equally, wonderfully clear.  [Have
any of you ever visited crystal clear, deep Aquarena Springs in San Marcos,
Texas, or swum in Hamilton's Pool outside Austin? --to name two of thousands
of examples.]

    Ray Stanford