Ridgetop, Tennessee

[pahsophist]

My partner and I have been vacationing in the Nashville area and we decided to go to the Ridgetop formation for a little fossil collecting. Since I'm a noob, I'd love some help in IDing these fossils.

This is the location at which we collected; it was by the side of Route 41:

Crinoid stem?

Another crinoid stem.

Not sure. Crinoid?

Coral?

Not sure what kind of shell. Some kind of mollusk?

Oyster-like mollusk?

Not sure.

Brachiopods?

Thanks, everyone!

[JimB88]

forth pic is a nice example of trace fossil. The 'oyster-like mollusk is more likely an inarticulate brach,and the 'not sure' is a pecten. The age of the formation will help in nailing down a genus. The coral is indeed a rugose or horn coral.

[JimB88]

I did some research on the age and it will depend on how close to Nashville you are..the closer to Nashville you get the more Ordovician the sediments are, theres a thin strip of Silurian and the two Mississippian formations from Ridgetop north; which with the productid brachs is most likely. In which case the inarticulate is most likely Orbiculoidea, the horn coral either Zaphrentis or Neozaphrentis, and the pecten most likely Limipecten.

[pahsophist]

Thanks! Yes, I was understanding that the local area contained Ordivician and some Silurian, but I had no idea where precisely we were collecting from. There was a dearth of information I could find. I couldn't even find Ridgetop! We were in the Ridgetop area but finally decided to pull over and collect from Route 41 because nobody in the local area seemed to know much of what we were talking about (and the directions were poor).

Regarding the 4th pic, it looks kind of branching. What kind of trace fossil do you think it is? We also saw many other rocks which looked like they could've been trace fossils; I picked a few up but I need to take them home and give them a good washing (and also get them under better lighting than just a hotel room lamp) to get a decent picture of them. They look kind of like worm tracks. But then again it could be something of the nature of the rock formation too, since there were a LOT.

Additional question: Is it likely that all of the shelled fossils I found were probably brachiopod? I don't know enough about their locales and habits.

Edited April 10, 2012 by pahsophist

[Xiphactinus]

Thanks! Yes, I was understanding that the local area contained Ordivician and some Silurian, but I had no idea where precisely we were collecting from. There was a dearth of information I could find. I couldn't even find Ridgetop! We were in the Ridgetop area but finally decided to pull over and collect from Route 41 because nobody in the local area seemed to know much of what we were talking about (and the directions were poor).

Regarding the 4th pic, it looks kind of branching. What kind of trace fossil do you think it is? We also saw many other rocks which looked like they could've been trace fossils; I picked a few up but I need to take them home and give them a good washing (and also get them under better lighting than just a hotel room lamp) to get a decent picture of them. They look kind of like worm tracks. But then again it could be something of the nature of the rock formation too, since there were a LOT.

Additional question: Is it likely that all of the shelled fossils I found were probably brachiopod? I don't know enough about their locales and habits.

The 4th fossil is a fenestrate bryozoa. I think the one after the coral is another coral, but more weathered. All the other shells are brachiopods of various types. Nice finds!

[JimB88]

The 4th fossil is a fenestrate bryozoa. I think the one after the coral is another coral, but more weathered. All the other shells are brachiopods of various types. Nice finds!

Not to sound combative but how do you get a Fenestella out of that? There is no definite structure which would indicate that. A better closer pic would help the issue. The 'not sure' is definitely a pecten not a brach I have found several with the hinge intact.

[pahsophist]

Here's an additional image from Pic#4, if that helps in the debate:

And another from #6:

In person, #6 does look shell-like, with its more rounded form. The pattern looks a wee similar to the shell in #8, the one labeled "not sure". If that helps.

[Xiphactinus]

Not to sound combative but how do you get a Fenestella out of that? There is no definite structure which would indicate that. A better closer pic would help the issue. The 'not sure' is definitely a pecten not a brach I have found several with the hinge intact.

No problems! Debate is good. It's a pretty classic bryozoa. I'm 99% sure on the "not sure" being a brach too. Here's a link to a bunch of Tennessee fossils. You'll see the same bryozoa and brach's here.

http://www.nashvillefossils.com/fieldtrips/parsonsfieldtrip/parsons.html

[JimB88]

with the better pic Ill agree with the bryo, but not the other one

Heres some of mine

If he was near Ridgetop TN then he was in the middle Mississippian in which pectens have been found. And there is no flat brachiopod with heavy radial ribs like that (many productids do, but there were far from flat.)

Just my 2cents