A Pirasocrinid Crinoid from the Pennsylvanian Holdenville Formation

[Mochaccino]

I would like to share a beautiful and possibly important crinoid in my collection from the Pennsylvanian Holdenville Formation of Oklahoma, USA. This specimen is best identified as Plaxocrinus sp. aff. P. dornickensis as originally described by Harrell Strimple in his 1961 paper "Late Desmoinesian crinoid faunule from Oklahoma", and confirmed by Pennsylvanian crinoid expert Peter Holterhoff. It was prepared masterfully by Mike Meacher.

 

It is a member of the family "Pirasocrinidae",  which is a prevalent group of crinoids especially in the Pennsylvanian. They are characterized by a low, saucer-shaped cup with three anal plates, axillary first primibrachials and various spinosity on the arms, and most notably a prominent highly-specialized "umbrella-like" anal sac that terminates as a platform of plates surrounded by a circlet of laterally-projecting spines.

 

Aside from simply wanting to show off one of my favorite fossils, there are a couple of reasons I think sharing this publicly could be useful. First off, articulated pirasocrinids are generally very rare in the fossil record, especially of this genus. It is thought that these crinoids had weak sutures between plates which made them highly-vulnerable to disarticulation. The vast majority of remains are found as loose anal/brachial spines and occasional calyxes, as shown below. 

 

https://snr.unl.edu/data/geologysoils/fossils/nebrinverthughes.aspx

 

Likely because of this, formal descriptions and pictures of pirasocrinid crowns are scarce in the literature and it is difficult to find public references on what articulated specimens look like, especially of how the spines of the arms and anal sac are configured. Though on my specimen the arms are not 100% complete all-around, enough is preserved to describe the full structure of the arms and the nature of the spinose primibrachials. Moreover, the exceptionally-preserved and prepared anal sac shows nearly the full extent of its articulation. Note the couple of near-complete brachial and anal sac spines, whose extraordinary lengths exceed the width of the calyx.

 

The second reason this specimen could be important is more specific. In Strimple 1961, Plaxocrinus sp. aff. P. dornickensis was described on just a single specimen; the calyx shown below:

 

Atypically for the genus, this calyx has a very smooth outline owing to flat, non-bulbous basals and nonimpressed, almost imperceptible sutures. Strimple concluded this species to be closely-related to but not conspecific with true Plaxocrinus dornickensis (which is a slightly older species than the Holdenville fauna, according to Dr. Holterhoff); hence the "aff." in the identification. Essentially, as far as formal description in the literature is concerned, the full crown of this crinoid is unknown. I have also not personally seen any other confirmed crowns of this species from the Holdenville Formation. All-in-all, this specimen could be quite significant for showing the previously-unknown arms and anal sac of Plaxocrinus sp. aff. P. dornickensis on an articulated crown, which might help further its description.

Edited March 23 by Mochaccino

[FossilDAWG]

What an amazing specimen!   
I believe you know @crinus, he has published several papers with a crinoid specialist and he might be able to suggest someone you could work with to get this published.

 

Don

[Mochaccino]

4 hours ago, FossilDAWG said:

What an amazing specimen!   
I believe you know @crinus, he has published several papers with a crinoid specialist and he might be able to suggest someone you could work with to get this published.

 

Don

Thanks! Indeed I do, crinus actually helped me acquire this piece unprepped, though I was uncertain of its identity until recently. Even after prep it took quite a while researching and asking around.
 

Speaking of which, I am also familiar with the crinoid paleontologists that crinus has worked with; Bill Ausich and Forest Gahn among them. However, they have told me that their focus and expertise are not in late-Paleozoic Pennsylvanian/Permian crinoids. The most prominent experts I could find in this area are Peter Holterhoff, who is no longer working in paleontology, and Georgy Mirantsev, who is in Russia and working on the local crinoid fauna. Unfortunately current crinoid paleontology research is far from prolific, and Pennsylvanian/Permian crinoids are especially obscure and neglected. I would be happy if my specimen is actually significant enough to contribute and publish, but unfortunately as of now I simply don't know of many actively pursuing this area of research. For now, hopefully this post is enough to put this specimen "out there", so to speak.

Edited March 22 by Mochaccino

[NickG]

Wow! SO COOL!

 

There are other pirasocrinoids described in the Appalachian Basin which is obviously very eastward of yours. You may want to look into John Burke's various papers (1940s-1970s) on the crinoid fauna of the Appalachian basin for comparative purposes. Strimple went out of his way to dunk on Burke (I'm not sure if it was a personal beef, but the writing is quite animose if it were simply a scholarly dispute), but Burke did extensively figure his material -- and almost all the papers are open access -- which may help you a lot. I know I (and friends) have found very similar looking crinoids to yours in the Glenshaw Formation. If yours are Late Desmoinesian, they are just a wee bit older than ours (Missourian). It would make sense though if there were similar faunas, because the height of the marine transgression in the Missourian would have brought more midcontinent fauna eastward.

[Mochaccino]

6 hours ago, NickG said:

Wow! SO COOL!

 

There are other pirasocrinoids described in the Appalachian Basin which is obviously very eastward of yours. You may want to look into John Burke's various papers (1940s-1970s) on the crinoid fauna of the Appalachian basin for comparative purposes. Strimple went out of his way to dunk on Burke (I'm not sure if it was a personal beef, but the writing is quite animose if it were simply a scholarly dispute), but Burke did extensively figure his material -- and almost all the papers are open access -- which may help you a lot. I know I (and friends) have found very similar looking crinoids to yours in the Glenshaw Formation. If yours are Late Desmoinesian, they are just a wee bit older than ours (Missourian). It would make sense though if there were similar faunas, because the height of the marine transgression in the Missourian would have brought more midcontinent fauna eastward.

Very interesting, clearly I haven't looked extensively enough in the literature, as I have never seen crinoids from this area! Good figures are definitely helpful, as the figures in Strimple 1961 are outdated, to say the least. I will look into Burke's work, thanks!

[NickG]

There are several papers on Desmoinesian midcontinent and midwest crinoids published after 1961.

 

Johnson and Suneson (1995) offer a comprehensive review of macrofossils of Oklahoma, including the Pennsylvania, which has a lot of citations in it which might aid your search - https://www.researchgate.net/profile/Kenneth-Johnson-21/publication/308100262_Rockhounding_and_earth-science_activities_in_Oklahoma_1995_workshop/links/57d9c8c908ae0c0081efbd0d/Rockhounding-and-earth-science-activities-in-Oklahoma-1995-workshop.pdf#page=20

 

Webster and Kues, 2006 describe Pennsylvanian crinoids from New Mexico and illustrate them extensively which might help you- https://geoinfo.nmt.edu/publications/periodicals/nmg/28/n1/nmg_v28_n1_p3.pdf

 

Strimple and others describe several crinoid taxa that have wide ranges in the Pennsylvanian (Missourian - Virgilian)- https://kuscholarworks.ku.edu/bitstream/handle/1808/3742/paleo.paper.042op.pdf?sequence=3&isAllowed=y

 

etc. Since many of these are geographically and temporally wide ranging, you might also check what was published on crinoids from the same time interval or slightly younger or older from states like IA, NE, etc. 

 

Good luck! If you have trouble accessing papers you find, please DM me and I'll help you get PDFs.

 

 

 

[Mochaccino]

5 hours ago, NickG said:

There are several papers on Desmoinesian midcontinent and midwest crinoids published after 1961.

 

Johnson and Suneson (1995) offer a comprehensive review of macrofossils of Oklahoma, including the Pennsylvania, which has a lot of citations in it which might aid your search - https://www.researchgate.net/profile/Kenneth-Johnson-21/publication/308100262_Rockhounding_and_earth-science_activities_in_Oklahoma_1995_workshop/links/57d9c8c908ae0c0081efbd0d/Rockhounding-and-earth-science-activities-in-Oklahoma-1995-workshop.pdf#page=20

 

Webster and Kues, 2006 describe Pennsylvanian crinoids from New Mexico and illustrate them extensively which might help you- https://geoinfo.nmt.edu/publications/periodicals/nmg/28/n1/nmg_v28_n1_p3.pdf

 

Strimple and others describe several crinoid taxa that have wide ranges in the Pennsylvanian (Missourian - Virgilian)- https://kuscholarworks.ku.edu/bitstream/handle/1808/3742/paleo.paper.042op.pdf?sequence=3&isAllowed=y

 

etc. Since many of these are geographically and temporally wide ranging, you might also check what was published on crinoids from the same time interval or slightly younger or older from states like IA, NE, etc. 

 

Good luck! If you have trouble accessing papers you find, please DM me and I'll help you get PDFs.

 

 

 

 

Much appreciated! Several of these I have indeed come across in my prior research, but not all.

[crinus]

On 3/22/2024 at 1:50 AM, Mochaccino said:

Thanks! Indeed I do, crinus actually helped me acquire this piece unprepped, though I was uncertain of its identity until recently. Even after prep it took quite a while researching and asking around.
 

Speaking of which, I am also familiar with the crinoid paleontologists that crinus has worked with; Bill Ausich and Forest Gahn among them. However, they have told me that their focus and expertise are not in late-Paleozoic Pennsylvanian/Permian crinoids. The most prominent experts I could find in this area are Peter Holterhoff, who is no longer working in paleontology, and Georgy Mirantsev, who is in Russia and working on the local crinoid fauna. Unfortunately current crinoid paleontology research is far from prolific, and Pennsylvanian/Permian crinoids are especially obscure and neglected. I would be happy if my specimen is actually significant enough to contribute and publish, but unfortunately as of now I simply don't know of many actively pursuing this area of research. For now, hopefully this post is enough to put this specimen "out there", so to speak.

While it is true that Forest and Bill are more interested in early Paleozoic crinoids, I am not as certain about Lena and Davey, the other two paleontologist that co-authored the Brechin Papers.  Both of them are now at the U of Oklahoma and your crinoid is from that area.  They have an extensive collection of Pennsylvanian and Permain material to work with at the Noble Museum.  Have you contacted either of them.  They are professors with grad students that may also be interested in working on something like this. 

[Mochaccino]

1 hour ago, crinus said:

While it is true that Forest and Bill are more interested in early Paleozoic crinoids, I am not as certain about Lena and Davey, the other two paleontologist that co-authored the Brechin Papers.  Both of them are now at the U of Oklahoma and your crinoid is from that area.  They have an extensive collection of Pennsylvanian and Permain material to work with at the Noble Museum.  Have you contacted either of them.  They are professors with grad students that may also be interested in working on something like this. 

That's a good point, and I believe the U of Oklahoma actually might be housing the main Holdenville Fm. collection that was originally used for Strimple's 1961 paper. I know Lena (Selina Cole) is currently the Invertebrate Paleontology Collections Manager at their Museum, so she should have access to those specimens! The only issue is that she doesn't seem too responsive. I've tried contacting her a couple times via email (albeit with different questions) and haven't received any replies in at least a few months. David Wright is the assistant curator so I could also reach out to him directly I suppose. I did try contacting the Invert Curators through the U of Oklahoma's website to ask about this Holdenville crinoid's identification, but again no reply for the past few months. I'll post any updates if I get any replies.

Edited March 23 by Mochaccino

[Tidgy's Dad]

What a beautiful specimen.

[crinus]

23 hours ago, Mochaccino said:

That's a good point, and I believe the U of Oklahoma actually might be housing the main Holdenville Fm. collection that was originally used for Strimple's 1961 paper. I know Lena (Selina Cole) is currently the Invertebrate Paleontology Collections Manager at their Museum, so she should have access to those specimens! The only issue is that she doesn't seem too responsive. I've tried contacting her a couple times via email (albeit with different questions) and haven't received any replies in at least a few months. David Wright is the assistant curator so I could also reach out to him directly I suppose. I did try contacting the Invert Curators through the U of Oklahoma's website to ask about this Holdenville crinoid's identification, but again no reply for the past few months. I'll post any updates if I get any replies.

If Lena is not replying I would have to conclude that your emails are somehow ending up in her spam.  Try contacting Davey and he can tell her that you are trying to contact her. You know that they are married.  If neither works, I will try to contact her and inform her of your desire for contact.

[Mochaccino]

40 minutes ago, crinus said:

If Lena is not replying I would have to conclude that your emails are somehow ending up in her spam.  Try contacting Davey and he can tell her that you are trying to contact her. You know that they are married.  If neither works, I will try to contact her and inform her of your desire for contact.

That's definitely possible, sometimes it's hard to tell. I'll try reaching Davey Wright. Thanks Joe!