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Re: New ref (Mosasaur bite marks)
Ralph Chapman wrote:
> I just saw this reference and had to mention it on the list. It is:
> Kase, T., P.A. Johnson, A. Seilacher & J.B. Boyce. 1998. Alleged
> mosasaur bit marks on Late Cretaceous ammonites are limpet
> (patellogastropod) home scars. Geology 26(10):947-950.
Actually, they are referring to Anisomyon (a marine limpet-like
pulmonate). Internal molds of large Placenticeras shells from the
Kremmling Birdbath locality often have molds of Anisomyon which had been
attached to the inside of the body chamber. They form a smooth, low
conical structure pointing into the mold of shell. They are never found
on the phragmacone (chambered portion of shell) (Wolfe and Kirkland,
1986 "after Emmett Evanoff").
Actual tooth marks of Mosasaurs are actual punctures through the shell
itself. They occur in lines across both the body chamber and the
phragmacone. The margin of the puncture is crushed with radiating cracks
in the shell. Ones I have found are in agreement with those described by
Kauffman and Kesling (1960)in fitting the dentition of Clidastes very
well. I have not seen these on molds of ammonites but can assure you
that they would leave a very different impression on an internal mold.
So as with many things, two views are correct under different
Kauffman, E. G. and Kesling, R. V., 1960, An upper Cretaceous ammonite
bitten by a Mosasaur. Contributions Museum of Paleontology University of
Wolfe, D.G. and Kirkland, J.I. 1986, The Kremmling Paleontological
Resource Area, Middle Park, Colorado. in Kauffman, E. G., (ed.)
Cretaceous Biofacies of the central part of the Western Interior Seaway:
A field Guidebook, NAPC IV, University of Colorado, Boulder, p. 199-210.
- New ref
- From: "Ralph Chapman" <Chapman.Ralph@NMNH.SI.EDU>