Date:         Thu, 29 Apr 1999 21:49:37 -0400
Reply-To:     Conchologists of America List <CONCH-L@UGA.CC.UGA.EDU>
Sender:       Conchologists of America List <CONCH-L@UGA.CC.UGA.EDU>
From:         Kay Lavalier <liavik@EARTHLINK.NET>
Subject:      Re: Cephalopod Info/ Bite Marks
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Andrew Vik
Tampa, FL., USA
liavik@earthlink.net
 
Andrew R.:
 
I was the one who first broached the subject of marine saurian predation on
ammonites. I cannot remember the source, but the book I saw had a very
convincing illustration of the V-shaped bite mark of a mosasaur in the shell of
a large discoidal ammonite. There were six holes, arranged as follows:
.         .
  .     .
    .  .
 
This seems to me to be too symmetrical to have been caused by six different
limpets (there were also tooth marks on the reverse side). I will see if I can
re-locate this source.
 
Andrew V.
 
Andrew K. Rindsberg wrote:
 
> Some time ago, Nora Bryan wrote about the difficulty of distinguishing
> limpet scars from bite marks on fossil ammonites. Erle Kaufmann interpreted
> the holes as punctures made by mosasaurs in the 1960's. Recently, Kase and
> others (including Dolf Seilacher) convincingly showed that some holes on
> ammonites are limpet scars in:
>
> Kase, T., Johnston, P. A., Seilacher, A. & Boyce, J. B. 1998. Alleged
> mosasaur bite marks on Late Cretaceous ammonites are limpet
> (patellogastropod) home scars. Geology, 26(10): 947-950.
>
> What you have to realize is that the eminent researchers did not study the
> same ammonites, though they did work on specimens from the same age and
> formation. Seilacher wanted to examine Kaufmann's ammonite, but this
> specimen was lost several years ago, so it is no longer available for
> study. If it has mosasaur bite marks, no one can tell for sure now. It
> could be that they are both right in different cases. As Walt Whitman said
> (more or less), "And if I contradict myself, very well, I contradict
> myself. I am large; I contain multitudes." Nature might say the same.
>
> David Schwimmer (the REAL vertebrate paleontologist living in Columbus,
> Georgia, not the actor on "Friends") has documented bite marks of sharks in
> Cretaceous dinosaur bones. He can distinguish marks made in "green" bone
> (that is, fresh bone) and in old, brittle bone. As to whether sharks made
> the holes, he has excellent evidence: Some of the holes have shark teeth in
> them. Sharks shed their teeth frequently and they sometimes rip out while
> they are feeding.
>
> Andrew K. Rindsberg
> Geological Survey of Alabama
> Tuscaloosa, Alabama, USA
 
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