Trigonostoma Gastropod Help Needed - Stone City Fmtn (Whiskey Bridge)

[WyomingRocks!]

Hello everybody, I am starting this topic as I need some help with identification of some Trigonostoma type fossils I found at Whiskey Bridge. I think they may be my favorite type of gastropods I found there. There are 3 types listed in Emerson book but I think I have more than that. The picture here shows 7 specimens (5 & 6 are the same, one and I will start from the left in this discussion. 1. this one looks very similar to T. penrosei but the main difference is that the shoulders are rounded, not flat topped like a normal Trigonostoma. The ribs are more prominent and spaced further apart. The aperture is a different shape and it has 3 folds on the columella instead of 2 like T. penrosei. The line and spiral ornamentation is basically the same and the umbilicus is covered up by the callus. 2. also looks similar to T. penrosei (and somewhat similar to a Bonellitia parilis but I ruled out B. parilis due to the ornamentation being different, aperture has a flat outline on top and has 3 distinct folds on the columella) but is shorter and more squat. It has periodic large ribs showing where the aperture was located at. It has a fairly flat topped shoulder and the ornamentation is more pronounced. It has 3 folds on the columella. 3. Trigonostoma panones juniperum 4. Trigonostoma penrosei 5 & 6. unknown type that is more of a T. babylonicum style but has a more pronounced rib structure, that are straight and do not have a slant to the left as the other Trigonostoma types do. 5 is a more juvenile specimen than 6 as the ribs disappear and the only ornamention left is prior aperture locations on the more adult one. 6 has serial dentation on the out lip and 5 does not. 7. Trigonostoma babylonicum.

If anybody has any ideas please let me know. Or if better pictures are needed I will try my best at that.

Thanks, Stephen

Edited November 20, 2013 by WyomingRocks!

[WyomingRocks!]

Close-up of 1-4.

[WyomingRocks!]

Close-up of 5-7.

[WyomingRocks!]

Apertures of 1-4.

[WyomingRocks!]

Apertures of 5-7.

1. I found 2 of.

2. I only found 1.

3. Found several.

4. Found several.

5 & 6. Found 4.

7. Found several.

Again, thanks for any help!

I have several more unidentified from Whiskey Bridge and will put those up also.

Edited November 20, 2013 by WyomingRocks!

[WyomingRocks!]

I decided to add this Trigonostoma babylonicum to show the 'spire' it has.

[Coco]

Hi,

I can't help you, but they are marvelous

Coco

[donckey]

Hi Stephen,

Some beauties you've got there

I am not familiair with eoceen gastropodes so I can't help you with the right ID's.

But since Trigonostoma gastropodes are among your favorites, I like you to show some different Trigonostoma sp. from Miste (Winterswijk) in the Netherlands.

Middle-Mioceen, Miste member.

I only have a modest collection from Miste and I am not a specialist, but I'm glad that I found six species of the ten species know till now

The latest species (extremely rare) is found only a month ago by Henri Jansen and is the Trigonostoma (trigonostoma) protigonostoma Sacco, 1894. Also extremely rare is T.(Misteia) mistense A.W. Janssen, 1984. The two others I did not find (yet ) are T. (T.) lindeni and a T. (Ventrilia) sp.

Peter

[WyomingRocks!]

Hi Stephen,

Some beauties you've got there

I am not familiair with eoceen gastropodes so I can't help you with the right ID's.

But since Trigonostoma gastropodes are among your favorites, I like you to show some different Trigonostoma sp. from Miste (Winterswijk) in the Netherlands.

Middle-Mioceen, Miste member.

I only have a modest collection from Miste and I am not a specialist, but I'm glad that I found six species of the ten species know till now

The latest species (extremely rare) is found only a month ago by Henri Jansen and is the Trigonostoma (trigonostoma) protigonostoma Sacco, 1894. Also extremely rare is T.(Misteia) mistense A.W. Janssen, 1984. The two others I did not find (yet ) are T. (T.) lindeni and a T. (Ventrilia) sp.

Peter

Trigonostoma extractrixcomb.jpg

apertum3maal.jpg

Trigonostoma barnardicobi.jpg

Trigonostoma geslini josephcombi.jpg

Trigonostoma planispirumcomb.jpg

Trigonostoma pouwicombi.jpg

Peter, thank you very much for the pictures of the Trigonostomas' found in your area. I like T. geslini josephinae and T. pouwi the best. Looks like you are able to find well preserved fossils over there.

Stephen

[old dead things]

Whiskey Bridge? Could you give a general location where you found these.

Most of the gastropods I have found are not from Wyoming, but a few in the Wamsutter area of southcentral Wyoming and a few in the Green River formation in SW Wyoming in the fish quarry (ies).

Jim

[WyomingRocks!]

Jim,

I found these at a site in Texas. I was down there for work. I have found some gastropods here in Wyoming but not many. Lots of clams, some shark teeth and a few ammonites with some small gastropods mixed in. I have looked near Wamsutter and picked several pieces of the turritella agate that is around there and in one area near Riverton I found some shark teeth, possible Mosasaur vertebra, and other odds n ends but it was on the reservation and I was able to get permission for one day only to hunt that site. I know that there is a good site north of Rock Springs where a lot of invertebrate fossils are found but I don't know the exact location.

Stephen

[jkfoam]

Congratulations,

That is a very nice collection of Trigonostoma from the Whiskey Bridge site in Texas. I have collected there many times and I don't think I ever found as many of those specimen as you found. With respect to the identifications I think for specimen No. 1 I would consider Buccitriton texanum. The absence of a prominent umbilicus points me in that direction. I cannot help with specimen No. 2. I would like to have a better view if the aperature. For specimen No. 3 I would I dentify it as Trigonostoma panones juniperum. For specimen No.4 I would identify it as Trigonostoma penrosei. And for specimen No.s 5,6 and 7 I would identify them all as Trigonostoma babylonicum. Please note that this is just my opinion, others may disagree. Specimen No.6 shows some crab predation and regrowth on the aperature, not uncommon.

You may want to refer to another reference book to confirm identifications. Look at "The Claibornian Scaphopoda, Gastropoda and Dibranchiate Cephalopoda of the Southern United States", Bulletins of American Paleontology, Vol. 7, 1937, by Kathern Van Winkle Palmer. This is, in my opinion, one of the primary references for the Eocene mollusca. It is available on line. It is cumbersome to use on-line because of its size.

Again, great finds.

Jim