Any ideas what this is?

[Larry E. Matthews]

It looks way too symetrical to be a coral. That is a perfect "cross" in the center, which could be four basal plates for a crinoid calyx.

Of course, the symetry could be an "accident". It could even be an FLR.

(FLR is the geologic term for "Funny-Looking Rock", a rock that looks like it ought to be something, but really isn't)

I've seen FLR's on eBay, listed as Dinosaur Heads, etc. Always a good laugh !!!

Larry E. Matthews
NSS #6792-F

[tncaver]

Does Kid Rock qualify as an FLR?

[Larry E. Matthews]

If Kid Rock isn't something that isn't what it is "cracked up to be", I don't know what is.

Maybe he is a FLRS: Funny Looking Rock Star.

He can't seem to come to Nashville, without getting arrested for something.

Larry E. Matthews
NSS #6792-F

[Squirrel Girl]

OK, here's what my friend wrote. He suggested I send the picture to someone else we went to school with (who did his dissertation on conodonts).

From looking at your fossil photo again, it looks like it is in fairly grainy rock, implying high energy. It looks like whatever it is is about 5 or 6 cm across; it also looks like it could be arguably bilaterally symmetrical, rather than radially symmetrical. While I can't rule out a rugose coral, I don't particularly like that explanation - remember, the rugae are from the growth lines parallel to the aperture, not longitudinally. It also looks like it was originally calcitic or replaced by coarsely crystalline calcite (from the photo, I suppose white chert might be a possibility, but I'd expect more relief in a cave).
Given those observations, it looks like something that might have been flattened and rugose to keep it in place in a high-energy environment, perhaps even partially buried, which would help with preservation. It could be a bivalve, like the Trigonia you find so abundantly in the oolite shoals around Austin (and which is a strongly rugose bivalve) I'm not sure if the view is a transverse cut through one valve, or possibly two valves flopped open along the hinge (hence, the apparent plane of symmetry). Just tell eveyone it's incertae sedis, and they'll be happy.

[Anonymous_Coward]

Okay, check this one out.



Anybody know what this is? I think I do. It is slightly larger than a golf ball and is found in Permian age limestone.

[Wormster]

Okay, check this one out.



Anybody know what this is? I think I do. It is slightly larger than a golf ball and is found in Permian age limestone.

s that's where i left my tiny table soccer ball. lol

[Teresa]

Now *that* looks like one of the hexagonaria coral varieties similar to the Petosky Stone--state fossil of Michigan.

[George Dasher]

Back to the original "fossil"...

It doesn't look like a fossil; more like a cave formation.

How about a 'mite that formed on sediment, and then the sediment washed away?

No idea what the second thing is. A bucky ball or a soccer ball?

[gillip]

As to the origial fossil - At first I thought that it is an echinoderm of some kind, probably a section through the crown. My guess was pterotocrinus, such as the one seen at:
http://www.uky.edu/KGS/fossils/crinoid.htm
That would fit with Mississippian age limestone, but the symmetry doesn't match. It could be a wierd cross-section.
I have a hard time seeing it being a holdfast because you usually don't see that kind of symmetry in a holdfast. I thought that one cirri usually comes off one segment in the holdfast, not many radiating off one, but I could be wrong.
Another thought was that it could be a bryozoan, such as Evactinopora, but they usually have 4-8 spines, so this specimen has too many. There can be divisions in Evactinopora, which are mutual walls that are shared by zooecia, but again the symmetry doesn't make any sense.
There is nothing like it in Shimer and Schrock Index Fossils of North America, and they have about everything.
I am stumped.

[CaverSteve]

I think that you have a blastoid.

[Illinois Caver]

My gut reaction would call it from the echinoid. How big is the little critter? That would help a bit.

[Squirrel Girl]

I would have agreed with Teresa about the golf ball, except that Hexagonaria are Devonian, and if the rock really is Permian, that can't be it.

Plus, the individual units don't show coral septa, and the outlines are extremely pentagonal. I'm leaning towards an echinoderm. A blastoid seems as reasonable as anything.

How big is it?

[Anonymous_Coward]

As I said, the soccer ball fossil is slightly bigger than a golf ball, so I would guess about 4 cm in diameter. It is definitely Permian in age. Some of the sections or plates are hexagonal, but as you noticed, most of them are pentagonal. At the time, I guessed it was probably a blastoid, and inventoried it as such. However, when I looked at blastoid calyxes online, I couldn't find one like this. The ones I found online were Mississippian age.

I think that echinoid is a great guess. We often find sea urchin spines in this rock. Also, tons of huge crinoid stems. Some of the crinoid shaped stem segments have a five pointed, star-shaped core, (pentagonal like the soccer ball sections). Maybe some of them are actually blastoid stems. I think I remember five-sided as being a characteristic of blastoids, but it has been nine years since I took invertebrate paleontology.

I'm sure if we talk about this long enough, some expert will show up and set us straight. I bet it's either a blastoid calyx or a sea urchin!

As far as the first mystery object is concerned, I think it looks much more like a fossil than a speleothem.

[Larry E. Matthews]

Check that fickle finger out in the first photo. This thing is way bigger than any blastoid I've ever seen.

I'm still sticking with crinoid. And, I saw some beautiful crinoid fossils for sale at the Nashville Gem and Mineral (and Fossil) show on December 8. It was easy to see the similarity of some of them to this "thing".

Rememeber, this "thing" in the photo is eroded, it's not a perfectly preserved fossil.

Larry E. Matthews
Professional Geologist
NSS #6792-F

[Larry E. Matthews]

Check that fickle finger out in the first photo. This thing is way bigger than any blastoid I've ever seen.

I'm still sticking with crinoid. And, I saw some beautiful crinoid fossils for sale at the Nashville Gem and Mineral (and Fossil) show on December 8. It was easy to see the similarity of some of them to this "thing".

Rememeber, this "thing" in the photo is eroded, it's not a perfectly preserved fossil.

Larry E. Matthews
Professional Geologist
NSS #6792-F