jamesp
Cave Dweller 
Member since October 2012
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Post by jamesp on Mar 13, 2014 12:41:16 GMT -5
The blotches look stromtalite. The center hole look s like a vent on an urchin/echinoid. But the whole enchilada makes me think whale/shark disc(between the vertebrae). If it has a marrow (look in the chunk missing) i say disc. They often have similar holes. Here is a disc God help us from a whale. Awful big for a shark. Some are oval...    |
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grayfingers
Cave Dweller
Member since November 2007
Posts: 4,575 
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Post by grayfingers on Mar 14, 2014 9:00:42 GMT -5
James, thanks for the info! I spent a couple hours this morning surfing the fossil forum and other sites and still am not able to find a like specimen. I looked at disk pads too, seems it could be either. . . there are some early sand dollars that were more simple looking. I see a reddish hue inside the break, marrow?. Took a couple more photos.(Misted it for more definition.) This side is slightly concave.  Next two pics are other side, slightly convex. Note how the hole is at a angle through the piece.   |
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jamesp
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Member since October 2012
Posts: 36,601
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Post by jamesp on Mar 14, 2014 9:20:28 GMT -5
The angular approach of the hole leans toward sand dollar/urchin/echinoid as opposed to disc. But a complete lack of 5 patterns kinda kills that theory.
The sections lean toward disc or may just be fractures. Leaning toward fractures and not a natural pattern. I wonder if you found it in a marine fossil enviro ?
I see oval discs. They are usually convex and the vertebrae sockets concave. But shark discs are quite variable. That angular hole entry messes w/me. If you do not
mind I will post it on the fossil forum and see if those guys can figure it out.
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grayfingers
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Member since November 2007
Posts: 4,575
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Post by grayfingers on Mar 14, 2014 9:37:16 GMT -5
Thanks! That would be great!
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,601
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Post by jamesp on Mar 14, 2014 9:56:26 GMT -5
It's done.
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Post by pghram on Mar 20, 2014 21:45:45 GMT -5
Neat find, I'm looking forward to the answer.
Rich
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panamark
fully equipped rock polisher
Member since September 2012
Posts: 1,343
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Post by panamark on Mar 20, 2014 23:18:32 GMT -5
Stone age era Indiana blade from a spinner? LOL
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,601
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Post by jamesp on Mar 21, 2014 7:02:27 GMT -5
The fossil forum seemed baffled to. Many were saying that it is a concretion. Looks too symetrical to me to be such.
One thought it was possibly an artifact. So far it is a mystery.
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grayfingers
Cave Dweller
Member since November 2007
Posts: 4,575
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Post by grayfingers on Mar 21, 2014 7:26:39 GMT -5
Aha, it must be the sand dollar "missing link" If so, it could be named Clypeasteroida Primo (primitive)
Thanks James, if those guys are stumped it may remain a mystery.
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