Crinoid Help- Plus Suspect Item

[Bullsnake]

Upper Pennsylvanian

I'm unsure of the formation, other than it is likely Lansing group (Missourian Series), with a chance of being Douglas group (Virgilian Series).

Found atop a weathered limestone exposure along with numerous small horn corals; various small brachiopods- small chonetids being predominant; very small crinoid columnals, and sparse plates and spines.

The three larger specimens are bullet shaped, ~1cm long and ~1cm wide.

The slightly smaller suspect item is more of an ovoid shape, ~1cm long and ~7mm at the widest point.

Other differences include a deeper center hole in the ovoid specimen that measures ~4mm. The other three are more of a shallow depression.

Fine surface detail appears different between the 'bullets', and the 'ovoid'.

No apparent stem attachment point on any of the specimens.

Closeup of tops:

Bullet:

Ovoid;

Surface details:

Bullet:

Ovoid:

I would like to mention that sponge has been suggested as a possibility for the ovoid shape.

Thank you for looking!

Edited November 15, 2014 by Bullsnake

[FossilDAWG]

These look like Agassizocrinus to me. In Agassizocrinus the basals are fused into a solid cone, which were massively thickened and likely served as a weight to anchor the crinoid to the sea floor. The rest of the calyx usually disarticulated after death, so the basal cone is the most common way one finds this crinoid.

Don

[Bullsnake]

These look like Agassizocrinus to me. In Agassizocrinus the basals are fused into a solid cone, which were massively thickened and likely served as a weight to anchor the crinoid to the sea floor. The rest of the calyx usually disarticulated after death, so the basal cone is the most common way one finds this crinoid.

Don

Thank you, Don.

Is it possible to identify loose plates, or arms (should I find any) to at least associate them for collection?

[FossilDAWG]

Here is a photo of a more complete specimen (the photo is from Crinus's excellent web site). The individual plates of the calyx and arms look fairly nondescript to me, due to the lack of ornamentation. A specialist might be able to distinguish them from Platycrinus or other unornamented plates.

Don

[Bullsnake]

Thank you!

[Herb]

nice specimens,Don. I only find the basal cups, The specimens on the link you gave are spectacular!!

Edited November 15, 2014 by Herb

[Archimedes]

Sure its a Paragassizocrinus not Agassizocrinus, Agassizocrinus only occur in the upper Mississippian

All of them look to be Paragassizocrinus tarri

Edited November 19, 2014 by Archimedes

[Herb]

looks like "2 Para".

[Bullsnake]

Sure its a Paragassizocrinus not Agassizocrinus, Agassizocrinus only occur in the upper Mississippian

All of them look to be Paragassizocrinus tarri

Ah, thank you Archimedes.

I did run across it (Paragassizocrinus) in JStor, and have been leaning that way.

While reading on both, 'Index Fossils of North America' does mention that Agassizocrinus has been found through possibly the Permian (outdated info?). However, the focus was on Mississippian specimens which reinforced my suspicion of Paragassizocrinus.

Your post seals it for me

Now to figure out the outcrop. If it's Virgilian series, the journal states it as being rare/went extinct in that series.

I'm not holding my breath, but it would certainly be a plus on the cool factor.

I'm happy with the find either way though .

[Missourian]

Steve/Bullsnake and I visited the same exposure recently. We both found a number of the bullet-shaped things. I found four:

Largest one:

Granular detail:

Five-sided pattern:

Two others:

[Missourian]

One thing I find interesting is that these are fairly numerous at this site, but they haven't shown up anywhere else. The local environment must have been particularly favorable for the otherwise rare to nonexistent crinoid.

[BobWill]

Yep you can plainly see the 5 way symmetry in those and faintly see it on one of Bullsnake's pictures showing close-up of tops, labeled bullet:

[Bullsnake]

Steve/Bullsnake and I visited the same exposure recently.

Glad you came over, Mitch.

And I appreciate the identity of the strata. One of these days I'll catch on .

Here is the site:

I'll soon begin a Hunting Trips thread with some more pictures of the layers, and another quick stop Mitch and I made.

[Archimedes]

Congratulations on finding a new locality for Paragassizocrinus. Though they are not found at many localities they are generally common along a bedding plane when found. Their sparse fossil record normally occurs in the Pennsylvanian outcrop belt from E Kansas/ W Missouri to central Texas. This locality appears to be one of the most northerly occurrences of them in the Missourian, upper Pennsylvanian.

[Herb]

I have dozens of Aggissizocrinus sp. from he M.Mississippian of KY.

[Bullsnake]

Congratulations on finding a new locality for Paragassizocrinus.

Thank you, Archimedes. And again for the ID confirmation.

I have dozens of Aggissizocrinus sp. from he M.Mississippian of KY.

Let's see 'em, Herb! (If you don't mind)

[LanceH]

Here's a Texas example I recently cobbled together from loose parts:

Edited December 29, 2014 by LanceH

[Bullsnake]

Here's a Texas example I recently cobbled together from loose parts:

2006-12-27-105-800.jpg 2006-12-27-121-800.jpg

2006-12-27-107-800.jpg

Wow, thank you, Lance!

Did you have to clean them up any, and if so, how?

It seems most of the TX fossils I've seen on here already have a much cleaner preservation than ours.

[LanceH]

That's how they are found at the one good locality near Mineral Wells.

There's another ring of half size plates that go around the top and level it off but I didn't have enough loose ones of the right size to go around. Then the plates above that are part of the arms shown in the image FossilDAWG posted.

Edited December 29, 2014 by LanceH

[LanceH]

Oh just found this!

The paper "The Genus Paragassizocrinus in Oklahoma" (OGS circular 55) is online:

http://www.ogs.ou.edu/pubsscanned/Circulars/circular55.pdf

Edited January 1, 2015 by LanceH

[Bullsnake]

Oh just found this!

The paper "The Genus Paragassizocrinus in Oklahoma" (OGS circular 55) is online:

http://www.ogs.ou.edu/pubsscanned/Circulars/circular55.pdf

Thank you, sir! I will read ASAP>

[Bullsnake]

Incidentally, here is a little story behind the find.

http://www.thefossilforum.com/index.php?/topic/51515-2014-season-finale-pennsylvanian-of-kansas/