Ordovician in Tennessee (Help!)

[Terri]

Kevin, since you have snow on the ground and can't get out hunting, I think I'll post a bunch of fossils and ask a a lot of annoying questions so you'll have something to do.

 

[Architeuthoceras]

Please do

 

[Terri]

This rock (app. 8 by 9) has a lot going on, I'll show a series of pics. may take a min.
but in the first few you'll see the round structures and once again I haven't a clue. I've done a lot of searching but haven't found anything similiar. In the 3rd pic. the deflated looking thing to the right of the circular one, I have seen something very close, but i can't find it!

 

[Terri]

There are some thick chunks of shell here also, 3-4 mm, I haven't seen this before either (just left of center). And to the right, below the ruler possibly a small cephalopod?

 

[Architeuthoceras]

There is a lot going on in that rock. It may take a while to sort it all out.

If that small thing on the right side isn't a cephalopod... something just kinda says crinoid...

The round thing has me baffled

 

[DWhatley]

Yeah! I saw that little cone shaped thing with the lines and wondered but felt stupid asking At least I am seeing some of the possibilities in the pictures!

 

[Terri]

Yay D! You should know by now that stupid questions are allowed on my threads. I have learned most of what I know by asking what probably seem like not very bright questions. And that little fossil does look cephish but after Kevin pointed it out I see the possibility of crinoid. So I'll take another look at it.

 

[Terri]

The round thing has me baffled

Here's a slightly different view showing the 'round thing" and the crinoid. Did you notice that there are two of the round things? The other one is above and just to the right a little, it's more broken than the other one.

 

[DWhatley]

Is it possible that it (the round thingys) could be some kind of nut or plant pod rather than an animal?

 

[Terri]

Good question D, the evolution of land plants did begin during the Ordovician period, but seed-bearing plants didn't appear in the fossil record for another 85 million years or so. If these fossils were a little younger that would certainly be something to look at, this article is excellent Embryophyte - Wikipedia check out the Horse Chestnut mega-spore, but I'm pretty sure the timing is all wrong. Kevin?

 

[Architeuthoceras]

Is it possible that it (the round thingys) could be some kind of nut or plant pod rather than an animal?

An Ordovician plant would be quite amazing, a seed even more so! Wonderful observation though.

In the last photo, it looks round enough to be an orthocone shell with the convex side of a septa inside. The hole don't look much like a siphuncle though.

 

[Architeuthoceras]

Snuck one in on me Terri. I like your answer better than mine.

 

[Terri]

 

[Terri]

Here's another view of the whole rock, then a few closer pics. of some of the other fossils in the rock, maybe they will give us a clue, with another "round thing" we really need to figure it out so we can quit calling them "round things". the second pic. was supposed to be first but anyway, as you can see there's another "round thing," maybe a ceph to the right center?

 

[DWhatley]

When were barnacles first alive?