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Crinoid Aboral Cup?


West4me

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Went out today and did some scrambling around in a new location.

Mississippian

Burlington Limestone

I think they are crinoid aboral cups. If so they are the first I have found.

post-3106-012512300 1277343598_thumb.jpg post-3106-004301200 1277343600_thumb.jpg

post-3106-082271900 1277343601_thumb.jpg

"You have to listen. It is under the rocks."

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West4me,

Cool find! :)

Unfortunately, I know little about Criinoids. :blush:

Congratulations on this if it is your first Crinoid cup!

Whatever it is, I like it! ;)

Regards,

    Tim    -  VETERAN SHALE SPLITTER

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West4me,

Cool find! :)

Unfortunately, I know little about Criinoids. :blush:

Congratulations on this if it is your first Crinoid cup!

Whatever it is, I like it! ;)

Regards,

I don't know anything either, I am just going off of this sketch:

post-3106-044731300 1277348558_thumb.gif

"You have to listen. It is under the rocks."

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Went out today and did some scrambling around in a new location.

Mississippian

Burlington Limestone

I think they are crinoid aboral cups. If so they are the first I have found.

post-3106-012512300 1277343598_thumb.jpg post-3106-004301200 1277343600_thumb.jpg

post-3106-082271900 1277343601_thumb.jpg

I believe it could be a holdfast, the attachment point for the stalk. I'm not an expert on Burlington crinoids, but irregularity of the plating and flat, discoid shape doesn't look like a cup to me. Here's a holdfast from the Ordovician for comparison: http://drydredgers.org/crinoid4.htm

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I believe it could be a holdfast, the attachment point for the stalk. I'm not an expert on Burlington crinoids, but irregularity of the plating and flat, discoid shape doesn't look like a cup to me. Here's a holdfast from the Ordovician for comparison: http://drydredgers.org/crinoid4.htm

Thanks for the resource, that seems like a more likely candidate.

"You have to listen. It is under the rocks."

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I believe it is a EUTROCHOCRINUS fairly common in the Burlinton ls.

That's a possibility: http://www.geology.ohio-state.edu/~ausich/EutrochocrinusChrysti.jpg

It seems very flat for a Eutrochocrinus cup. But it could be the tegmen, the top part of the cup. Which would make this an oral view, and make the circular impression the attachment point for the anal tube rather than the stalk.

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I believe it could be a holdfast, the attachment point for the stalk. I'm not an expert on Burlington crinoids, but irregularity of the plating and flat, discoid shape doesn't look like a cup to me. Here's a holdfast from the Ordovician for comparison: http://drydredgers.org/crinoid4.htm

I believe it is a EUTROCHOCRINUS fairly common in the Burlinton ls.

Holdfast was a worthy guess, but I think Archimedes is right-on here.

Both 'Fossil Crinoids' (Hess) and the 'Treatise on Invertebrate Paleontology' (Moore, Teichert) have specimens that look very similar. Especially when they are fro the Mississippian Burlington Limestone, it seems hard to look anywhere else.

That's a possibility: http://www.geology.ohio-state.edu/~ausich/EutrochocrinusChrysti.jpg

It seems very flat for a Eutrochocrinus cup. But it could be the tegmen, the top part of the cup. Which would make this an oral view, and make the circular impression the attachment point for the anal tube rather than the stalk.

I considered the tegman possibility, and one of the images in 'the Treatise' even has one with a tegman that is broken right where this specimen appears to be broken.

However, when I look at the individual plates that make up this item, they seem more like what are on the aboral side of the specimens in the literature.

So, it could be either.

I'd like to see some closer, higher resolution photos if at all possible.

.

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Come visit Sandi, the 'Fossil Journey Cruiser'

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WIPS (the Western Interior Paleontological Society - http://www.westernpaleo.org)

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"Being genetically cursed with an almost inhuman sense of curiosity and wonder, I'm hard-wired to investigate even the most unlikely, uninteresting (to others anyway) and irrelevant details; often asking hypothetical questions from many angles in an attempt to understand something more thoroughly."

-- Mr. Edonihce

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Here are closer pictures of the two specimens.

post-3106-019553900 1277773745_thumb.jpg The thumbnail is black on my computer but clicking on it makes takes you to the image.

post-3106-069603300 1277773748_thumb.jpg

Edited by West4me

"You have to listen. It is under the rocks."

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