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Cretaceous bivalve/mollusk?


madness

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My opinion, the hole in yhe middle of the fossil seems natural, ao I don't think its a bivalve. Maybe some sort of mollusk? But dony take my word seriously until someone whos an expert in this comes by and gives a better answer.

If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM!

 

 

Mosasaurus_hoffmannii_skull_schematic.png

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It looks like a piece of ammonite.

Could you take photos of all the faces : those that i have circled, the other side and the parts in a circle or a rectangle, We must see those parts fronting your camera.

AC_BW4.jpg.757f824d0e8bc4a032280ad99af1b722.jpg.883742b768d34ca90085f8c3a429087d.jpg

theme-celtique.png.bbc4d5765974b5daba0607d157eecfed.png.7c09081f292875c94595c562a862958c.png

"On ne voit bien que par le coeur, l'essentiel est invisible pour les yeux." (Antoine de Saint-Exupéry)

"We only well see with the heart, the essential is invisible for the eyes."

 

In memory of Doren

photo-thumb-12286.jpg.878620deab804c0e4e53f3eab4625b4c.jpg

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Like in those photos, for example :

PC250009.JPG.afeaec2eb33d31b20b2deb8ed288ce30.JPGPC250010.JPG.faed675c4a2bc8b3c9b67eabb9190946.JPG

theme-celtique.png.bbc4d5765974b5daba0607d157eecfed.png.7c09081f292875c94595c562a862958c.png

"On ne voit bien que par le coeur, l'essentiel est invisible pour les yeux." (Antoine de Saint-Exupéry)

"We only well see with the heart, the essential is invisible for the eyes."

 

In memory of Doren

photo-thumb-12286.jpg.878620deab804c0e4e53f3eab4625b4c.jpg

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I agree that it's a nautiloid.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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Interesting. I thought it was an internal cast of something like a gryphaeidae. Here are some more photos. Using the original photo as reference:

 

The left:

 

left.thumb.jpg.c471d3170fde668d84805d264be0696f.jpg

 

The right:

right.thumb.jpg.f77ec0aae1b18cebf88e5c467b70bd0d.jpg

 

The top:

top.jpg.24b4de04632ea2e68866e3f2a8adbe87.jpg

 

The back is just matrix. I can see what I interpret as shell where the fossil meets the matrix. This is what lead me to think it was an internal cast. I found loads of this "shell" fossil in little bits all over in this location.

 

shell.jpg.772798ecb520c505359f1a29026e7595.jpg

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It's one of the weirder "inoceramids". The genus is Volviceramus.  There are three species known from the Austin Chalk. It looks mostly like V. involutus. 

It's a great specimen, a keeper for sure.

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1 hour ago, FranzBernhard said:

Is the shell fibrous?

I think I would call it fibrous! :P There are distinct transverse/perpendicular lines, by which I mean running from the outside to the inside. It's hard to get a good shot because of the shape of the fossil. Here are three pieces we found in the same location that have similar characteristics - though the shell on the fossil in this thread shows no signs of curvature like the bigger pieces here. The shell on the fossil under question is about 3 mm thick.

 

 

shellcrosssection.jpg

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5 minutes ago, erose said:

It's one of the weirder "inoceramids". The genus is Volviceramus.  There are three species known from the Austin Chalk. It looks mostly like V. involutus. 

It's a great specimen, a keeper for sure.

I was typing a comment when your reply came in! Something else I've never heard of. Seems to be a lot of that these days. :) Off to do some more research!

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Your fragments are from inoceramid shells as well. They show the classic "prismatic" structure of those bivalves.  There are quite a few different genera, subgenera and species of "inoceramids" in the Austin Chalk.  But there are also a few that do occur in the lower formations as well as higher up in the strata.

 

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The pattern reminded me of a inoceramid but that is a wierd curve, curse you convergent evolution!

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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I'm no expert, but I still thought it looked like something from the Gryphaeidae family maybe along the lines of the exogyrinea subfamily. 

But I searched for Volviceramus here on the forum and came up with this reference posted by @abyssunder and that looks like a pretty close representation of it. See the link.

 

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That's what I was searching for to my reply. Thanks for finding it. :)

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

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