Pennsylvanian Sponge or Crinoid from Arizona

[DPS Ammonite]

Any idea what these silicified possible crinoids are?  Are they even crinoids? They are from the Pennsylvanian Naco Formation from near Payson. The ones in the photos (both sides are shown) are from 0.8 to 1.5 cm wide. @crinus

 

These two references might be of help. Anyone have access to the photos from these?

Webster, G., & Olson, T. (1998). Nacocrinus elliotti, a New Pachylocrinid from the Naco Formation (Pennsylvanian, Desmoinesian) of Central Arizona. Journal of Paleontology, 72(3), 510-512. 

 

Webster, Gary; Elliott, David. (2004). New information on crinoids (Echinodermata) from the Pennsylvanian Naco Formation of central Arizona. The Mountain Geologist. 41. 77-86. 

[Tidgy's Dad]

I have one of them :

Mmm, that didn't work.

Not sure it's of much help,though.

Here's a link :

https://www.researchgate.net/publication/252321735_New_information_on_crinoids_Echinodermata_from_the_Pennsylvanian_Naco_Formation_of_central_Arizona

[DPS Ammonite]

Thanks Adam. I agree it does not look like any from Webster and Elliot 2004.

 

[Innocentx]

42 minutes ago, DPS Ammonite said:

Are they even crinoids?

I never saw any similar. These are unusual, to say the least.

[ynot]

Sponge?

[Innocentx]

I'm looking for any 5 sided action here, but not seeing it.

[Tidgy's Dad]

This is Nacocrinus from the other Webster paper :

[Nimravis]

Looks like some new type of fruit, try eating one. LOL

[DPS Ammonite]

1 minute ago, Nimravis said:

Looks like some new type of fruit, try eating one. LOL

It might be forbidden. Who knows what calamity will befall us.

[DPS Ammonite]

Could these fossils be an internal mold of a crinoid head? I note that chertized brachiopods, crinoid columns and small horn corals all with their exteriors are present in the area. It seems a little odd that the exterior of a crinoid would not also be preserved.

[Innocentx]

https://pubs.geoscienceworld.org/jpaleontol/article-abstract/83/1/45/83775/pre-and-postmortem-skeletal-modifications-of-the?redirectedFrom=fulltext

 

Here is plate of images from above article:   

 

 

[goatinformationist]

Possible coral?

[Innocentx]

It is interesting that the crinoids in the above plate show symmetries other than the usual five. Pre and post mortem skeletal changes don't necessarily explain what's happened with regards to @DPS Ammonite's specimens except to show that some pathology may be present, as in figures 16, 17, 18, and 19.

 

I'm suggesting there may be pathologies in these specimens. Another idea is there may have been some major environmental upheaval at an early stage of development which caused them to continue growing around a broken off piece whatever they were attached to. There are no cups visible and I don't see evidence of crinoid so not even sure what these are but I'm going with the initial suggestion here.

 

Without the suggestion of crinoid, I would say the upper left specimen looks like a coral, possibly Cladochonus or similar. The upper right and lower left also look like immature corals but I'm not familiar with which they might be. The one at lower right almost looks like a ball that got rolled in disarticulated stems, but of what don't know.

 

The big question for all these is, how did they get this ball form with no evidence of being attached to anything?.

[BobWill]

I was finding something like this near Lake Murray in Oklahoma many years ago. I'll try to find some to post. I always thought they were some kind of coral but never found out. They look a little like a Devonian fossil found in Nevada and Arizona, Brachyphyllum woodmani.

[Innocentx]

16 minutes ago, BobWill said:

Brachyphyllum

I hadn't thought of plant material.

[BobWill]

14 minutes ago, Innocentx said:

I hadn't thought of plant material.

There's a genus of plant and coral named Brachyphyllum. I was thinking of the coral. It's the wrong age but maybe there's something similar from the Penn.

 

Sorry! I'm spelling that wrong. It's Pachyphyllum woodmani.

[BobWill]

I found these in the Pennsylvanian of Oklahoma. I assumed they were coral at the time but never posted them for an ID. Do these look the same?

[DPS Ammonite]

7 minutes ago, BobWill said:

I found these in the Pennsylvanian of Oklahoma. I assumed they were coral at the time but never posted them for an ID. Do these look the same?

Thanks Bob. They look real similar. What formation? What are they made of: calcium carbonate? What is scale? Anything similar from Jacksboro?

 

[BobWill]

i don't know the formation around lake Murray but there were some of these right on the beach at the main park there. These range from 10 to 20mm across. I've never seen anything like this at Jacksboro or the other Texas Pennsylvanian sites. There are some images that show up for comparison  if you google that corrected name above but I don't know what the closest thing from the Pennsylvanian would be.

[BobWill]

I forgot to answer the other question. They are cream-colored and very hard and do not react to vinegar.

[DPS Ammonite]

18 minutes ago, BobWill said:

I forgot to answer the other question. They are cream-colored and very hard and do not react to vinegar.

What about a scratch test for hardness with a steel blade.

[BobWill]

They leave a scratch on my pocket knife and the knife does not scratch them.

[DPS Ammonite]

9 minutes ago, BobWill said:

They leave a scratch on my pocket knife and the knife does not scratch them.

Thanks, they are probably chert. Same as mine

[BobWill]

I can't find a usable geo map of OK to nail down the formation. We're so spoiled here in Texas. I'll bet you miss having detailed maps that even come with a booklet describing the exposures. Anything like that in AZ?

[KimTexan]

There are 3 Pennsylvanian formations around Lake Murray. Deese, Dornick Hills Group and Hoxbar Group. There is also Antlers Sand, but it’s Cretaceous. 

Oops Oscar Group on the far NE side of lake. Deese is most common covering whole West and south sides.