Orbiculoidea capuliformis with preserved pedicle, Muncie creek concretion

[Jaybot]

I recently collected some Muncie creek concretions from the Kansas City area.  I had previously only found a few concretions, but this time I was fortunate enough to end up with about 10.

Several had Conulariid sections preserved, which I was excited about.  Back home, I cracked open the remaining concretions.  One of them had a tiny little brachiopod, and I didn't think much of it.  Later, looking at it under magnification, I was astounded when I found the remains of the preserved pedicle! 

This is where I am sad to say, that in my excitement, I forgot to take pictures of the fossil prior to me prepping around the shell to aid in id. 

Anyways, after prepping around the shell with a hand scribe, I was excited to find that it was also my first lingulate brach.

Orbiculoidea capuliformis

 

Sorry for making you read all of that, here are the photos:

 

 

 

Scale is in cm.

Here are several interesting articles/papers for anyone interested.

https://www.diva-portal.org/smash/get/diva2:373816/FULLTEXT01.pdf

https://www.researchgate.net/figure/a-b-The-brachiopod-L-chengjiangensis-represented-by-stout-pedicles-marked-by-numbers_fig1_24424671

 

Despite being small, there is a lot of potential with Muncie Creek shale concretions.  I learned a lot about them, and their existence, here on TFF.

@Missourian has found many astonishing finds, and I noticed that soft tissue preservation is prevalent in many of his best concretions.

 

Hope y'all enjoyed this.  Have a great day, and a great weekend

 

 

-Jay

[JamieLynn]

what a find! Congrats! 

[Jaybot]

8 hours ago, JamieLynn said:

what a find! Congrats! 

Thank you! 

[Tidgy's Dad]

Discinids, both living and fossil were sessile, not burrowing creatures like Lingula, so do not have a long pedicle.

They have a very short pedicle to anchor them to the hard substrate. A bit like a limpet does with its foot.

I think your pedicle is a geological feature not connected to the rather lovely fossil.

 

http://www.geology.cz/bulletin/fulltext/1161_mergl.pdf

"Solitary discinids, both fossil and extant, are fixo-sessile
invertebrates, attached by a pedicle to various hard substrates."

Edited February 11 by Tidgy's Dad

[Jaybot]

3 hours ago, Tidgy's Dad said:

Discinids, both living and fossil were sessile, not burrowing creatures like Lingula, so do not have a long pedicle.

They have a very short pedicle to anchor them to the hard substrate. A bit like a limpet does with its foot.

I think your pedicle is a geological feature not connected to the rather lovely fossil.

 

http://www.geology.cz/bulletin/fulltext/1161_mergl.pdf

"Solitary discinids, both fossil and extant, are fixo-sessile
invertebrates, attached by a pedicle to various hard substrates."

Thank you for your message!  I found the article very interesting, I didn't know anything about discinids until now

 

 

I found this section interesting:

 

''Length of pedicle. – Südkamp (1997) described finds of
Orbiculoidea? mediorhenana Fuchs, 1915 with remar-
kably long pedicles, but its pedicle size is probably a pre-
servational artefact (Otto 2000). ''

 

Upon further research, I learned that ''Pedicles of inarticulate species are extensions of the main coelom, which houses the internal organs.''

I agree with you that we are not likely looking at a abnormally long pedicle with my specimen, unless it is some growth defect (incredibly unlikely) or some undiscovered characteristic of capuliformis.  However, it is possible that Südkamp's specimen, as well as mine, is in fact the internal organs strewn outside of the shell, then preserved.  If the pedicle was attached to an object, but then torn off, half pulling its organs out with the pedicle, it then could have sank down and became preserved in the Muncie creek formation, which is known for excellent preservation.  Looking at my find with magnification, it does seem like 'something' is there, and not a geological feature.  Not only that, but it meets directly with the edge of the main valve.

 

Again, thank you so much for taking the time to write your message.

Have a great day!

 

-Jay

[connorp]

Sorry but have to agree with @Tidgy's Dad. I suspect it is a piece of carbonized plant material.

[Jaybot]

Since the characteristics of the line do not match up with the plant remains that I have found in Muncie creek concretions, and since it meets with the edge of the shell, I'll just label it with

Orbiculoidea capuliformis w/ soft tissue.  I truly appreciate your input @Tidgy's Dad, and if it wasn't for your message I would have continued believing that it was the pedicle.

I've learned a lot, thank you to everyone that gives input on my posts. 

Have a great day y'all!

 

-Jay

[Tidgy's Dad]

1 minute ago, Jaybot said:

I'll just label it with

Orbiculoidea capuliformis w/ soft tissue.

I see no suggestion that this is soft tissue of any type.

I am not sure it is connected to the valve interior, looks like another layer to me.

Brachiopods contain little organic matter inside, compared to the shell size, a lot of it is open space inside allowing for circulation of water to the lophophore.

The amount of material that your fossil shows looks too much for the interior volume of the shell to begin with, but include the actual empty volume of the shell and it really can't all fit in there.

N.B. The diagram is taken from the Treatise and only shows the musculature, but there isn't much more to a brachiopod barring a stomach and the lophophore.

[Jaybot]

4 hours ago, Tidgy's Dad said:

I see no suggestion that this is soft tissue of any type.

I am not sure it is connected to the valve interior, looks like another layer to me.

Brachiopods contain little organic matter inside, compared to the shell size, a lot of it is open space inside allowing for circulation of water to the lophophore.

The amount of material that your fossil shows looks too much for the interior volume of the shell to begin with, but include the actual empty volume of the shell and it really can't all fit in there.

N.B. The diagram is taken from the Treatise and only shows the musculature, but there isn't much more to a brachiopod barring a stomach and the lophophore.

Thank you for your message!

I have to agree with you after seeing the diagram you attached, and your explanation.  Thank you for helping me out with this one, and sorry if I was a bit too hopeful throughout.

Have a great day!

 

-Jay

[Tidgy's Dad]

3 hours ago, Jaybot said:

 

I have to agree with you after seeing the diagram you attached, and your explanation.  Thank you for helping me out with this one, and sorry if I was a bit too hopeful throughout.

S'okay, I do it myself.

It's sometimes hard to let go when you've got something fixed in your head that you want it to be.

I still sulk about some of'em.