A Few Keokuk Limestone/ Mississippian Unknowns

[minnbuckeye]

My Keokuk Limestone finds from this fall have now been cleaned and identified. I am struggling with a few and am reaching out for any suggestions to identification. Thanks!!

 

1. First up is a blastoid that can't be matched well with the three species to occur in the Keokuk. It is probably a weathered sample that makes identification tough for me.

 

 

 

 

 

 

2. A crinoid cup that I do not recognize. It is very round and smooth. Maybe it isn't a crinoid cup!

 

 

 

 

3. A second crinoid cup I can't identify.

 

 

 

 

4. A large gastropod that spirals backwards to most gastropods. Reminds me of Maclurites if this was Ordovician.  Straparolus looks similar but spirals normally.

 

 

 

 

5. And finally a specimen I thought was a fenstrate bryozoan until I looked closely and saw it lacked the netted appearance. Maybe a dendroid graptolite?

 

[crinus]

#2 is possibly an Azygocrinus.

Edited January 17 by crinus

[Mochaccino]

#1 at a glance resembles Globoblastus norwoodi from the Burlington, unless you're seeing something unusual with it? I don't know if it's reported from the Keokuk though.
 

#3 looks like the basal plates/basal circlet of a Platycrinites sp. crinoid

Edited January 17 by Mochaccino

[Mochaccino]

PS. #1. Cryptoblastus might be a better match actually, more elongated than Globoblastus

[minnbuckeye]

Thanks for all of the help! But I do need to ask @crinus his opinion on #2 being Azygocrinus. After looking at specimens on line, I can see the round nature of this cup fitting  Azygocrinus. But the images available show definite divisions where the crinoid plates but up to each other. This crinoid cup shows no marking that define the plates, just a smooth round body. Here are a few more pictures of the specimen. Do you still feel this is  Azygocrinus?

 

 

 

 

 

 

 

 

[crinus]

2 hours ago, minnbuckeye said:

Thanks for all of the help! But I do need to ask @crinus his opinion on #2 being Azygocrinus. After looking at specimens on line, I can see the round nature of this cup fitting  Azygocrinus. But the images available show definite divisions where the crinoid plates but up to each other. This crinoid cup shows no marking that define the plates, just a smooth round body. Here are a few more pictures of the specimen. Do you still feel this is  Azygocrinus?

 

 

 

 

 

 

 

 

Probably not Azygocrinus.  Difficult to tell as I am not seeing any plate structures.  It could easily be the base of any crinoid. 

I am curious if everyone is seeing the white line like some text is being blocked.  If there was more text after #2crinoid it is all blocked out for me.  I have seen this on several other posts.

[Coco]

2 hours ago, minnbuckeye said:

Merci pour toute l'aide ! Mais je dois demander@crinus son avis sur  le n°2 étant  Azygocrinus. Après avoir regardé des spécimens en ligne, je constate le caractère rond de cette coupe adaptée  à Azygocrinus. Mais les images disponibles montrent des divisions définies où les plaques crinoïdes mais les unes par rapport aux autres. Cette coupe crinoïde ne présente aucune marque définissant les plaques, juste un corps rond et lisse. Voici quelques photos supplémentaires du spécimen. Pensez-vous toujours qu'il s'agit d'Azygocrinus ?

Same for me. I use the black forum background and after "Azygocrinus" the text is in very light gray on a white background, so unreadable. I think it happens when you copy and paste.

 

Even by highlighting the text it remains unreadable.

 

Coco

[Fossildude19]

1 hour ago, crinus said:

Probably not Azygocrinus.  Difficult to tell as I am not seeing any plate structures.  It could easily be the base of any crinoid. 

I am curious if everyone is seeing the white line like some text is being blocked.  If there was more text after #2crinoid it is all blocked out for me.  I have seen this on several other posts.

 

 

This is likely due to a copy and paste. Not being blocked.

I have fixed it by removing the formatting.

[bockryan]

I can't ID it but #5 is very cool

[minnbuckeye]

3 hours ago, bockryan said:

I can't ID it but #5 is very cool

I totally agree. Was hoping someone recognized it (as well as the gastropod).

[Tidgy's Dad]

The fenestrates became extremely successful and diverse during the Mississippian.

Not saying it isn't a dendroid, but I reckon a bryozoan is more likely.

[minnbuckeye]

@Tidgy's Dad Thanks for the opinion. The definition of Fenestella  by Wikipedia states that it is a genus of bryozoans or moss animals, forming fan–shaped colonies with a netted appearance. Mine definitely has no netting. Is there a group of Bryozoa that are fan like without the netting? My search of images was unproductive. I have found multiple pictures of dendriod graptolites that look similar. Here is one example.

 

 

[Tidgy's Dad]

2 minutes ago, minnbuckeye said:

The definition of Fenestella  by Wikipedia states that it is a genus of bryozoans or moss animals, forming fan–shaped colonies with a netted appearance. Mine definitely has no netting. Is there a group of Bryozoa that are fan like without the netting? My search of images was unproductive.

 

Yes, that's the genus Fenestella.

The order Fenestrida / Fenestrata is very diverse and contains all sorts of forms.

But they are usually net like, I think, so I dunno.

 

[Tidgy's Dad]

Unitrypa is quite like this and can be without the horizontal connections but is only Devonian, I believe.

Penniretopora is found in the Mississippian but is nothing like this.