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Cyclocystoid?


Guest solius symbiosus

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Guest solius symbiosus

Anyone have any experience with cyclocystoids? I found this today(early Late Ordovician???), and I am hesitant to "call" it a one because of their extreme rarity. It could be a weathered holdfast, but I don't think so. At first I thought that it was an ossicle that had weathered, but upon closer inspection, it clearly is not. I was able to view a slab with 9 cyclocystoids last year that was found in the same member, but about 25 miles from this locality, and some of those were also, somewhat, disarticulated. Too, I pulled 7 crinoids from the outcrop today; 2 of which are nearly complete.

Thoughts???

post-179-1237510896_thumb.jpg

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I can only compare it to the one I found here last summer. I don't know how many species there are, but mine, and others I've seen photos of all seem to have a lot more plates around the rim than I see on yours, unless of course it is weathered and they just didn't show up in the photo.

post-77-1237511908_thumb.jpg

There's no limit to what you can accomplish when you're supposed to be doing something else

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Guest solius symbiosus

It is hard to discern in the photo, but I counted 36 under the microscope. It is weathered, but I'll see if I can get a better image.

Here is the abstract of a presentation given last year on the only other ones, that I am aware of, to be found around here. This is the slab that I saw last year.

http://gsa.confex.com/gsa/2007SE/finalprog...ract_118775.htm

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This is at magx20.

Yes, the segments are evident around the inner edge.

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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This is at magx20.

Difficult to tell from the picture. You have to be careful as dead crinoids then to curl into a circle. Your image is a bit out of focus, but I think I see a biserial pattern, suggesting maybe a crinoid arm that has curled.

crinus

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Guest solius symbiosus

I've pulled 50-60 crinoids from this outcrop, and if it is an arm, it is atypical. Though, I have found a few holdfasts that are similar, but they all show multiple rings. I'll post some photos of those later.

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  • 2 months later...

It appears to be a segment of a large crinoid stem, as if you were looking straight down onto it, but thats just my opinion

I like crinoids......

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Guest solius symbiosus

It might be a cirri from a stem, but I don't think that it is an ossicle. I have found holdfasts at this out crop that are similar.

post-179-1244491759_thumb.jpg

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It might be a cirri from a stem, but I don't think that it is an ossicle. I have found holdfasts at this out crop that are similar.

post-179-1244491759_thumb.jpg

Two weeks ago I found something like this in Lake Michigan and I am not sure what it is ?

Jevans

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Guest solius symbiosus
Two weeks ago I found something like this in Lake Michigan and I am not sure what it is ?

Post a pic and it can probably be IDed. The one above was found in Mid Ord rocks. In those rocks I have found numerous Reteocrinus sp., and the pinnules from one other genus not identified. I think that the holdfast is associated with the un-identified genus.

Here is another holdfast from rocks of similar age, but different outcrop. At this outcrop, I have found numerous Pychnocrinus sp. and a few of what are probably Archaeocrinus sp.

Width of pic about 6cm

post-179-1244585129_thumb.jpg

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Post a pic and it can probably be IDed. The one above was found in Mid Ord rocks. In those rocks I have found numerous Reteocrinus sp., and the pinnules from one other genus not identified. I think that the holdfast is associated with the un-identified genus.

Here is another holdfast from rocks of similar age, but different outcrop. At this outcrop, I have found numerous Pychnocrinus sp. and a few of what are probably Archaeocrinus sp.

Width of pic about 6cm

post-179-1244585129_thumb.jpg

Hey Solius

I am no expert on those cyclocystoides,but I tend to agree with Crinus that the plate structure in your mag doesn't quite look right. However, I think they were believed to have about 40 submarginal plates. They are cool buggers though. I collected one years ago in the Ordovician Verulum Formation up in Ontario.

Crabfossilstevel

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Post a pic and it can probably be IDed. The one above was found in Mid Ord rocks. In those rocks I have found numerous Reteocrinus sp., and the pinnules from one other genus not identified. I think that the holdfast is associated with the un-identified genus.

Here is another holdfast from rocks of similar age, but different outcrop. At this outcrop, I have found numerous Pychnocrinus sp. and a few of what are probably Archaeocrinus sp.

Width of pic about 6cm

post-179-1244585129_thumb.jpg

I am not really sure how to post pictures yet, once my son shows me I will get a picture. The only thing I can say it is tightly coiled together and have not seen anything like it yet except that one picture of yours. Thanks

Jevans

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Guest solius symbiosus
Hey Solius

I am no expert on those cyclocystoides,but I tend to agree with Crinus that the plate structure in your mag doesn't quite look right. However, I think they were believed to have about 40 submarginal plates. They are cool buggers though. I collected one years ago in the Ordovician Verulum Formation up in Ontario.

Crabfossilstevel

I have found a couple more of these since making the original post, and they are less dis-articulated and attached to a hardground(or other sessile organism). For those reasons, I'm thinking that it is the basal attachment for a stem. It is unlike any other arm that I have seen from this outcrop, and does not resemble any other ossicle found there. And, I have seen thousands from this bed.

Here is the "typical" crinoid found there:

post-179-1244594459_thumb.jpg

post-179-1244594491_thumb.jpg

post-179-1244594530_thumb.jpg

And the punnulate arm of an atypical:

post-179-1244594556_thumb.jpg

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