[Rockhounds] Galena Fossil ID?

[R. Peter Richards]

Looks like a nautiloid cephalopod.  Unlike the only(?) remaining  
species today, the chambered nautilus, many of the early ones had  
straight cones for shells, not coiled-up ones.  As I understand it,  
each of those chambers, now bisected by the breaking of the rock, was  
filled with gas but under control of the organism to control  
buoyancy.  I don't know how to they did it, however.

Pete Richards


On Feb 23, 2009, at 7:27 PM, John Siebel wrote:

> Enough about Kenny already. Here's yet another unknown for you  
> fossil folks. I remember seeing a lot of these in the limestone  
> along the RR tracks when I was a kid. This from Joe Daviess County,  
> Galena, Illinois.
> http://www.flickr.com/photos/31394106@N08/3305047146/
>
> Thanks - John
>
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___________________________________
R. Peter Richards
rpr at heidelberg.edu
Morphological crystallographer





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