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Please ID Crinoid Segment Placement


jewelonly

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I recently chiseled this piece out of a Mississippian road cut exposure in north Tn, Fort Payne Formation, with a generous assist from TFF member @Herb. I apologize for lack of proper scale, measuring approximately 6cm x 7cm x 5cm x 10cm. I used a dremel, soaking, and scrapping method to remove as much of the hard limestone, but cannot remove the rest as the dremel bounces off the solid crinoid hash remaining.

I am having difficulty with identifying where this would fit on the crinoid unless it is something similar to the proximal stem and branching arms shown on the illustrated figure by Ausich, W., Brett, C., Hess, H., & Simms, M. (1999). Crinoid form and function. Fossil Crinoids. 

http://paleoinver.materias.gl.fcen.uba.ar/index.php/download_file/view/106/129/

 

I appreciate the help! :) 

 

Thank you,

 

Leah

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Bottom

 

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Front (for reference)

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Side

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Top

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I think you've got a radice holdfast there - so the penultimate photo is upside down, and it's the distal end. Impressive chunks!

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Tarquin

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3 hours ago, TqB said:

I think you've got a radice holdfast there - so the penultimate photo is upside down, and it's the distal end. Impressive chunks!

 

 

@TqB, Thank you! That makes sense to me now. It is chunky which is why I struggled to identify its place on such a graceful form. :) 

 

IMG_8098.JPG

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Nice find Leah! Are those pieces in the background all from the same trip?

Dipleurawhisperer5.jpg          MOTM.png.61350469b02f439fd4d5d77c2c69da85.png

I like Trilo-butts and I cannot lie.

 

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Without seeing the first reply my thought was on crinoid anchoring system (holdfast). If Tarquin has the same idea, it could be true. :)

Just an example:

 

F15.large.thumb.jpg.be88281a774e6eddd86533c6b96b9a36.jpg

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" 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. "

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55 minutes ago, Darktooth said:

Nice find Leah! Are those pieces in the background all from the same trip?

 

@Darktooth , Thank you! Yes, that is all from the same trip! Crazy fun day in the crinoid zone! Here is a pic of most everything, including a couple of nice plates that I haven't even thought about prepping yet. :) 

IMG_8275.JPG

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26 minutes ago, abyssunder said:

Without seeing the first reply my thought was on crinoid anchoring system (holdfast). If Tarquin has the same idea, it could be true. :)

Just an example:

 

F15.large.thumb.jpg.be88281a774e6eddd86533c6b96b9a36.jpg

@abyssunder, Thank you! This illustration really helps. :) Here is a segment of another holdfast, perhaps. I'm not sure how it should be oriented but I'm thinking 45 degrees(?) 

IMG_8167.JPG

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Wow, tons of beauties! Excellent finds! ...and very good pictures, BTW. :)

 

Hard to say with certainty, but it could be also upside down or at an angle of 90 degrees.
The end views of the branches clearly indicate that they are from the anchoring system.

 

I see what you are referring to... :)

F10.large.jpg.91db8ca24bc42423fe845d88fe34b82b.jpg

Edited by abyssunder
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" 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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15 minutes ago, abyssunder said:

Wow, tons of beauties! Excellent finds! ...and very good pictures, BTW. :)

 

Hard to say with certainty, but it could be also upside down or at an angle of 90 degrees.
The end views of the branches clearly indicate that they are from the anchoring system.

@abyssunder, Thank you!! One cannot help but learn some good tips from the pros around here. :) 

 

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The last one in order could be a fragment from the grapnel. It might be similar to the one exemplified in Plate 3, fig.18, showing the distinct cirri levels.

 

IMG_8167.JPG.5d6e4006081e770206e393c58368c2f3.thumb.JPG.d89b6d8c9cde5b14f39538c8a34b6d1b.JPGID316_2.thumb.jpg.ee2f64e5d6f2c6b77f3a6f472c86753f.jpg

 

18, hypotype UC 40390, Locality 8, New York; side view of grapnel showing three distinct cirri levels, seven cirri are present altogether.

 

excerpt from here

 

 

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" 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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Those are some of the hugest crinoid stems I have ever seen! What amazing finds!  Now you need to find the calyx to go with that...

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----------------------------------------------------------------------------------------------------------------------------

Arizona Chris

Paleo Web Site:  http://schursastrophotography.com/fossiladventures.html

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15 minutes ago, abyssunder said:

The last one in order could be a fragment from the grapnel. It might be similar to the one exemplified in Plate 3, fig.18, showing the distinct cirri levels.

 

IMG_8167.JPG.5d6e4006081e770206e393c58368c2f3.thumb.JPG.d89b6d8c9cde5b14f39538c8a34b6d1b.JPGID316_2.thumb.jpg.ee2f64e5d6f2c6b77f3a6f472c86753f.jpg

 

18, hypotype UC 40390, Locality 8, New York; side view of grapnel showing three distinct cirri levels, seven cirri are present altogether.

 

excerpt from here

 

 

Wow!!! @abyssunder, that is an amazing illustration and reference link!!! Thank you so much! That really helps me make sense of a number of crinoid segments which can't be explained by a simple diagram. :) 

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4 minutes ago, Arizona Chris said:

Those are some of the hugest crinoid stems I have ever seen! What amazing finds!  Now you need to find the calyx to go with that...

@Arizona Chris, Believe me, I was looking! :) If I ever do, the surrounding population will know it! :D 

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I think that is a holdfast also, Leah. Nice pix.

 

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"Absence of evidence is not evidence of absence"_ Carl Sagen

No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go.

" I think, therefore I collect fossils." _ Me

"When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes

"can't we all just get along?" Jack Nicholson from Mars Attacks

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Thank you, Herb!! We wouldn't be having this discussion without your help! :) 

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Great collection, they look very similar to large Rhabdocrinus bits that we get in the UK Mississippian, they get up to 30mm diameter or so. I haven't seen holdfast pieces quite like that though.

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Tarquin

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Tarquin,  the Rhabdocrinus specimen uploaded for August 2016 Fossil of the Month is beautifully detailed and large. Such a lovely find. :) 

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Wow, that's the mother lode of crinoid pieces. The matrix pieces look pretty good, I don't think they need much prepping if at all.

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@Wrangellian, Yes, it was a very nice crinoid collecting day. I would like to prep some of the matrix pieces a little, but I will probably wait until I have an air abrasion tool. The dremel method I employed on the specimen in OP is too cumbersome for satisfying results. :) 

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I see what you mean. I would aim for a natural look, whatever method you use, but to me many of the stems on those matrix pieces look exposed enough as if Nature did all the work for you!

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Can you help me ID this Callovian or Oxfordian pluricolumnalium with cirri from Poland?

IMAG9707_1.thumb.jpg.9098b0679de6edc7195b719cad17f918.jpgIMAG9708_1.thumb.jpg.779b103b13c91e21fdcf572c26d08b50.jpg

IMAG9715_1.jpg.7b65123b2a40e0b0b95c9803737a140b.jpg

IMAG9711_1.jpg.fbb7676b419d22e677ee6eda9cd3ab9d.jpg

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I suppose it could be isocrinid pluricolumnal with the visible facet similar to the one below:

 

c15f003.jpg.bd95b805ed04a48d35520ca80698d221.jpg

(c) Articular facet of a columnal of the isocrinoid Neocrinus with symplectial articulation around the five petal-like areola areas (x9). (Courtesy of Stephen Donovan.)

 

picture from here

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" 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

My Library

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