Ordovician in Tennessee (Help!)

[Terri]

If the body chamber is on the bottom, it has a very constricted aperture.

This is what has me confused!

Any sign of the siphuncle in the phragmocone?

There's a convenient blob of stuff right where i would expect to see some sign of the siphuncle, I'll take a better look at it and post back later.

 

[Terri]

In the photos it does look as if the siphuncle is protruding from the aperture, looking at it here, it just looks broken, but I'm just not really sure. The side not shown above is sort of crushed in, I'll post a pic. with a couple more. (sorry about the quality of pics.)

 

[Architeuthoceras]

That looks better, a lot of the early paleozoic nautiloids had constricted apertures, just not as much as those first pics made it look. It don't look like the siphuncle coming out of the aperture anymore, like you pointed out, just broken. If you could scrape some of that white coating of the end, it looks like the siphuncle is there, in a sub-ventral location. Looks like a nice little breviconic cyrtocone.

 

[Terri]

Cool, thanks Kevin. With such a constricted aperture, it's hard to imagine what they looked like in life! Were this nautiloids typically small or did they get much larger?

If you could scrape some of that white coating of the end

I'll see what I can do with it. I have a few more that I found in the same little area with this one, just bits and pieces though, I'll post them later.

 

[Terri]

Well, I cleaned it up a little Kevin and I don't know if I'm seeing anything at all. I really expected to see something more definitive. There is a very faint circular depression, which I can really only make out with a magnifying glass.

I took a good 2 dozen pics.(blurry ones) before I realized that the resolution settings were turned down really low , which is why I haven't been able to get decent pics. lately. I'll take better pictures tommorrow(hopefully) and post then.

 

[Architeuthoceras]

Cool, thanks Kevin. With such a constricted aperture, it's hard to imagine what they looked like in life! Were this nautiloids typically small or did they get much larger?

See Phragmoceras and Hexameroceras on THIS page (The Fossil Book, p. 275), a couple of very constricted apertures, your guess is as good as anyone else's

 

[Terri]

Great link Kevin, thanks! I scraped some of the stuff off the top but I just don't think I see anything. Here's a pic.

 

[Terri]

Here a few bits and pieces found along with the fossil posted above, the first one maybe another cyrtocone with yet another gastropod in the living chamber? This one enlarges pretty decently.

 

[Terri]

....and this one, cyrtocone? I can get different views on most of these if needed..

 

[Terri]

Branching coral??

 

[Architeuthoceras]

Here a few bits and pieces found along with the fossil posted above, the first one maybe another cyrtocone with yet another gastropod in the living chamber? This one enlarges pretty decently.

Yes, hard to see if the gastropod is in or on the body chamber.

....and this one, cyrtocone? I can get different views on most of these if needed..

Cyrtocone

Branching coral??

Branching Bryozoan, all the small holes are typical of Bryozoans

 

[Terri]

Thanks Kevin!

 

[Terri]

Tiny gastropods, a section of a nautiloid, and a couple orthocones (unless they're gastropods). You can just make out suture lines on the nautiloid if you look closely enough, center bottom of rock and the ?orthocones right side center and top. The gastropods are all so small I wonder , are they a small species or juveniles?

 

[Architeuthoceras]

Looks like a couple of gastropod species, Those with a diamond shape are cool!

About the same as I found today, only mine are Triassic. I don't think it will ever stop snowing this year.

 

[Terri]

Awesome scenery as usual! At least you got out for a while. I love looking at these plates, so many different views, I spend hours with a magnifying glass and it seems every time I look I find something new, I'll have to take another look at the diamond shaped ones.

Still snowing?! None of that here, but we are getting at least bi-weekly storms with tornadoes, straight line winds, etc....