Bigby-Cannon Limestone

[Terri]

This isn't the best picture, but as soon as the weather clears up I will go back and get some better shots. If you zoom in to the posterior end you can just make out some suture lines (if I use any terms incorrectly please correct me, I am here to learn!) Any observations appreciated, will post more pictures with measurements soon.

 

[Architeuthoceras]

Just from the size and location of the siphuncle I would say an Endocerid. It looks like the fossil is half phragmocone and half body chamber

We still have a lot of snow on the ground out here, it is nice to see someone can get out and find stuff

 

[Terri]

That was the one day I had between the snow melting off and the rain starting,snow again by morning...

 

[Terri]

Here are a few more pictures of the last fossil I posted. It's 2.5 ft. long, I'm excited, it's the largest fossil I've found yet! The second picture is the living chamber and the third is at the end of the phragmacone. This was packed with mud, so I didn't know until I got it home that the siphuncle was exposed.

 

[Architeuthoceras]

Is the siphuncle a hollow tube? That is very large for an Ellesmerocerid, but looking at that closeup of the ?hollow siphuncle, and the relatively close spaced septa it is beginning to look like one.

 

[Terri]

It is actually hollow all the way around the siphuncle and the siphuncle looks crystalized, I am going to see if I have a better picture and post it if I do, if not I will try to get a better one tommorrow. It looks a little flat in the picture but the siphuncle is centered in the cavity. I apologize again for my poor descriptive skills, I hope what I am calling a siphuncle is actually the siphuncle.

 

[Architeuthoceras]

An annotated pic. On fossil cephs, everything inside and including the septal necks and/or connecting rings is considered part of the siphuncle. I can't see if there are connecting rings on your fossil, it looks like the septal necks just extend back to the preceding septum. It also looks like the crystals formed after lithification so I don't think they were deposited by the animal while it was alive, they just grew in the empty space where the original siphuncle was. The crystals in the center possibly grew on a Rod or other internal structure that the animal did deposit.

 

[Terri]

Awesome Kevin, thanks so much for doing that! Do you still think Ellesmerocerid, or do you need to see connecting rings to decide that? I have had the worst time getting decent pictures of this fossil, limestone does not photograph very well. I am going back out to look again but I don't think I am seeing connecting rings either.

I have found several more orthocones at the same location, all very much smaller, I will post them this evening if you would like to see them. I found them all within about a 200sq. ft. area. I am on my way back up there to see what I can find right now.

Thanks again, I have to look up half of everything you say, but I am determined to get it right.

 

[Architeuthoceras]

Yes, post more pics. Is there an outcrop you could photograph?

 

[Terri]

This first pic. I took from the roadside, the second was on top, which is where I found the fossils.
I am not sure about this at all, but it may be: Nashville Group; Bigby Cannon Limestone and Hermitage Formation.

The rest will be some of the orthocones I found there. I really haven't found a lot of other fossils, a few gastropods and some coral (I think it's coral) a few small brachiopods.

 

[Terri]

And a few more....

 

[Architeuthoceras]

Thanks for the outcrop photos Terri, looks like you have some nice rock there with a lot of bits and pieces of all kinds of critters

The rest will be some of the orthocones I found there.

Looks like the endosiphocone (Endosiphuncular deposits) from an Endocerid. I think I have seen some with a similar pattern, I will check on this.

And a few more....

Hard to tell on these, the one with the expanded siphuncle segments is an Actinocerid

I hope I can get out and start finding stuff now that spring is finally coming

 

[Terri]

Thanks again Kevin, I tried getting a better picture of the siphuncle on the large one (Ellesmerocerid?) but they really didn't show any more detail and I don't think there are any connecting rings.

I hope you get to start looking soon too, I need more pictures and posts to read. The bad thing about spring around here are the tornadoes, straight line winds, etc...some potentially moving through tonight. I would gladly trade your desert for my basin! I'm going to go look up big words now
Have fun lookin for stuff

 

[Architeuthoceras]

The endosiphocone is possibly from Allotrioceras, an Endocerid from the Family Allotrioceratidae

Wikipedia article Here

 

[Terri]

Hey Kevin! I found what (I think) is a section of a orthocone, it's not in very good condition. I found it at the same location as fossils 7-12 in this thread which (I think) is Bigby Cannon Limestone. It's about 11 centimeters long and about 11 centimeters wide. Is there enough detail for an id?