What are these tiny fossils?

[KCMOfossil]

I could use some help with the ID for these tiny fossils. I found them in the Pennsylvanian Subsystem, the Kansas City Group, at the top of the Winterset L.S. Member and at another site in the Kansas City Group that I cannot identify (I don’t know what it is). Most of the specimens I have found were in fist-size nodules of tan/yellowish limestone.

 

These specimens are all around 1 cm in size and the tiny nodes/spines are 1 mm or so. After having seen dozens of these specimens, I have observed that most of them consist of a round disc about 1 cm in size with the tiny “spines” pointing towards the center. Picture #3, however, shows one that is elongated rather than round.

 

In picture #2 I have circled the specimen with the "cap" still covering most of the spines in black and circled some of the exposed spines in blue.  In picture #5 I circled and area that contains the "cap" under which are the "spines".

 

I took these photos with my point and shoot camera on a tripod and my 10x loupe held against the lense.  It works surprisingly well, yet as you can tell the pictures vary in quality and are hard to focus.  I use a photo editor to crop the pictures so the images you see below are about 1/10 the area of the originals.  Any tips you can give me on getting better pictures of tiny fossils will be appreciated.

 

I look forward to any help you can give me.  

 

Russ

[DevonianDigger]

I don't know what they are, but they're really cool whatever they are!

[ynot]

My first thought is a crinoid holdfast. The other thought is a cluster of eggs.

Tony

[Rockwood]

Could be a mold of a heliolitid coral.

[TqB]

At that scale, they look like bryozoan moulds, especially clear in no.3.

[Rockwood]

Yah I should read these more carefully. (all wound up this morning I guess )

[KCMOfossil]

Rockwood, I notice you posted some pictures of a similar specimen here .  In fact, your pictures there look just like what I have been finding. 

 

Russ

[Rockwood]

51 minutes ago, KCMOfossil said:

Rockwood, I notice you posted some pictures of a similar specimen here .  In fact, your pictures there look just like what I have been finding. 

 

Russ

The scale is the critical feature that is observable. What is not obvious in that post, if it was indeed preserved, are the tabulae and perhaps tiny septa that would be in the larger tube shapes. Bryozoans of this form would not be that large.

[Herb]

looks like various parts of corals

[KCMOfossil]

Thanks to all of you.  I hesitated to put photo #3 in the post because I thought it could possibly be a different species from the rest; but I put it in because of the similarities to the others and it seemed probable that it was the same or a related species.  Upon thinking it over again, however, like Tarquin, I think it is possible that #3 is a mold of a branch bryozoan with a lateral sort of exposure.  The others, however, seem to  me not to be bryozoans.  They are also fragile, hard to preserve. and difficult to photograph.  As I mentioned above, I've seen dozens of them, but I haven't taken photos faithfully, although I have tried to retain as big and interesting of pieces of them as I could.  Rockwood's photos in the link I mentioned above are quite good.  The specimens I see are round or disc shaped, about 1 cm in diameter with 50 or so (I've not really counted) tiny fingers inside attached to the "shell" and pointing towards the center.  I will be checking further on your suggested IDs.  Thanks again for your input.

 

Russ

[TqB]

I think bryozoan is a good candidate for all of them, the tubes are too narrow for corals. Bryozoans come in many different colony forms, even in the same species sometimes.

[Missourian]

Yes, they are bryozoans. I've found some in the upper Winterset:

 

 

I think the unusual preservation may be due to dolomitization.

 

[KCMOfossil]

Thanks, Missourian, for your confirmation on that ID for the Winterset bryozoan.  One fascinating thing I have noticed with some of this beige limestone is the wonderful clarity of detail in the molds.  Often there are few casts, but the molds are very nice.  Tarquin, your suggestion makes sense in that it explains the great similarity between photo 3 and the rest.  Fistulipora, for example, can take many shapes.  However, I still puzzle over the consistent size and shape of most of the specimens I have seen.

 

Russ