Two Nautiloid Steinkerns?

[Mochaccino]

Hello,

 

Could I get some help identifying these two nautiloid steinkerns? Unfortunately no precise age/locality info on them but I think they might be from the Pennsylvanian or Permian of Kansas or Texas.

They are both around 8-9cm wide.

 

1. 

 

 

2.

 

Referring to this:

http://inyo2.coffeecup.com/kansasfossils/kansasfossils.html

 

I think #1. might be Metacoceras and #2. might be Liroceras. @Missourian I believe you are referenced in that post and you seem to be experienced in this fauna?

 

Thanks

[fifbrindacier]

The last one is for sure a nautiloid.

You can also visite that site :

https://www.txfossils.com/

[Missourian]

Very nice specimens!

 

#1 is Metacoceras if there are two rows of bumps, or Tainoceras if it has four.

 

#2 most likely is Liroceras.

[Mochaccino]

38 minutes ago, fifbrindacier said:

The last one is for sure a nautiloid.

You can also visite that site :

https://www.txfossils.com/

 

5 minutes ago, Missourian said:

Very nice specimens!

 

#1 is Metacoceras if there are two rows of bumps, or Tainoceras if it has four.

 

#2 most likely is Liroceras.

 

Thank you both! @Missourian I'm surprised my guesses were good, I just threw them out there based on appearance! Out of curiosity, are either of these particularly rare?

 

[Missourian]

34 minutes ago, Mochaccino said:

Thank you both! @Missourian I'm surprised my guesses were good, I just threw them out there based on appearance! Out of curiosity, are either of these particularly rare?

 

In my experience around Kansas City, cephalopods tend to be uncommon to rare. Besides orthocones, Metacoceras and Liroceras are the forms most likely to be found. They can be more numerous in isolated deposits. In KC, there is an oolitic limestone of limited extent that contains these two genera as well as some rare one I've seen nowhere else.

 

Basically, even where they are most numerous, you may find one now or then, but you can't just expect to find one on any given outing.

 

I can't vouch for Texas or other areas.

[Mochaccino]

14 minutes ago, Missourian said:

 

In my experience around Kansas City, cephalopods tend to be uncommon to rare. Besides orthocones, Metacoceras and Liroceras are the forms most likely to be found. They can be more numerous in isolated deposits. In KC, there is an oolitic limestone of limited extent that contains these two genera as well as some rare one I've seen nowhere else.

 

Basically, even where they are most numerous, you may find one now or then, but you can't just expect to find one on any given outing.

 

I can't vouch for Texas or other areas.

I see, very informative, thanks! Could I ask you to look at one more specimen? The photos aren't the best, but this one doesn't seem to have any nodes so it's probably something different. Domatoceras perhaps?

 

Edited November 14, 2022 by Mochaccino

[BobWill]

This last one appears to be Domatoceras sp. based on the possible squared-off venter. A view of the whorl profile can be helpful for identifying these. If I had found it in the Graham formation of Texas I would assume it was D. sculptile.

[Mochaccino]

3 hours ago, BobWill said:

This last one appears to be Domatoceras sp. based on the possible squared-off venter. A view of the whorl profile can be helpful for identifying these. If I had found it in the Graham formation of Texas I would assume it was D. sculptile.

 

Thank you very much for the ID!

[Missourian]

It appears to belong under Grypoceratidae. I've always been a bit unclear with the identity of these forms.

 

For reference and comparison, here are a few example in my collection:

 

I have tentatively labeled this as Titanoceras. It may actually be Domatoceras:

 

 

 

Domatoceras sp. In recent times, these large forms have been found among a megafauna at one site:

 

 

 

Stenodomatoceras sp. Note the tight whorl:

 

 

 

I don't yet have a name for these skinny forms:

 

 

 

 

The megafauna Domatoceras was found in the Westerville Limestone. All others are from the Winterset Limestone; both Pennsylvanian. All were found in Kansas City, Missouri.

[Mochaccino]

5 hours ago, Missourian said:

It appears to belong under Grypoceratidae. I've always been a bit unclear with the identity of these forms.

 

For reference and comparison, here are a few example in my collection:

 

I have tentatively labeled this as Titanoceras. It may actually be Domatoceras:

 

 

 

Domatoceras sp. In recent times, these large forms have been found among a megafauna at one site:

 

 

 

Stenodomatoceras sp. Note the tight whorl:

 

 

 

I don't yet have a name for these skinny forms:

 

 

 

 

The megafauna Domatoceras was found in the Westerville Limestone. All others are from the Winterset Limestone; both Pennsylvanian. All were found in Kansas City, Missouri.

 

Interesting, so several different forms exist! Thank you, very informative.

[BobWill]

Once again, it's the whorl profiles that are the most help with these. A Titanoceras is not only very large at maturity with a  diameter of 2 feet or more, the whorls are wider than high. They also have very think shells and the whorls have almost no overlap giving them a very open umbilicus.

[Mochaccino]

1 hour ago, BobWill said:

Once again, it's the whorl profiles that are the most help with these. A Titanoceras is not only very large at maturity with a  diameter of 2 feet or more, the whorls are wider than high. They also have very think shells and the whorls have almost no overlap giving them a very open umbilicus.

 

Wow, 2 feet, so around 30 cm!!! That name is very appropriate. This one is tiny in comparison. Hard to really see the umbilicus of that specimen in its current state, and it seems that's important for finer distinctions. But I definitely have some tentative IDs. Thank you.

[BobWill]

On 11/15/2022 at 10:45 PM, Mochaccino said:

 

Wow, 2 feet, so around 30 cm!!! That name is very appropriate. This one is tiny in comparison. Hard to really see the umbilicus of that specimen in its current state, and it seems that's important for finer distinctions. But I definitely have some tentative IDs. Thank you.

Of course they all start out small but having a view of the whorl profile tells us how evolute the coiling is so that tells us how open the umbilicus is and it tells us how the whorl height compares to the width. This advice is for identifying the purposed Titanoceras that @Missourian posted.

[Missourian]

I just ran across this site:

 

https://www.bagniliggia.it/WMSD/HtmFamily/GRYPOCERATIDAELS.htm

 

It turns out that my unidentified form above is Domatoceras umbilicatum.

 

That site will take a long time to look through to sort out many other id questions in my collection

[Mochaccino]

@Missourian @BobWill So I had a chance to take a closer look at the first nautiloid, and I believe it may have four rows of bumps. Does this seem the case? And would that make it a Tainoceras and not a Metacoceras?
 

[Missourian]

4 hours ago, Mochaccino said:

@Missourian @BobWill So I had a chance to take a closer look at the first nautiloid, and I believe it may have four rows of bumps. Does this seem the case? And would that make it a Tainoceras and not a Metacoceras?

 

Yes.

 

And that is a very nice specimen!

[Mochaccino]

10 minutes ago, Missourian said:

 

Yes.

 

And that is a very nice specimen!

 

Thank you. Any guess what species? It is from an old collection and I was told it was found off the coast of Australia, but I'm not sure if that info is correct. I searched for Tainoceras in that database you posted and it seems it doesn't occur in Australia. Also according to that database there seem to be several species described from the Pennsylvanian and Permian of the US. 

[FossilDAWG]

Some very nice nautiloids in this thread!!

Don

[Missourian]

11 hours ago, Mochaccino said:

 

Thank you. Any guess what species? It is from an old collection and I was told it was found off the coast of Australia, but I'm not sure if that info is correct. I searched for Tainoceras in that database you posted and it seems it doesn't occur in Australia. Also according to that database there seem to be several species described from the Pennsylvanian and Permian of the US. 

 

I think yours may be Tainoceras occidentale.

 

Not sure about yours being from Australia. The few references I checked don't indicate Carboniferous occurrences. With the uncertainty, the Pennsylvanian Midcontinent is still the best bet. Here's one I found in the KC Metro (Merriam Limestone; Parkville, MO) that I believe is T. occidentale:

 

 

 

Are there other types of fossils in the collection?

[Mochaccino]

6 hours ago, Missourian said:

 

I think yours may be Tainoceras occidentale.

 

Not sure about yours being from Australia. The few references I checked don't indicate Carboniferous occurrences. With the uncertainty, the Pennsylvanian Midcontinent is still the best bet. Here's one I found in the KC Metro (Merriam Limestone; Parkville, MO) that I believe is T. occidentale:

 

 

 

Are there other types of fossils in the collection?

 

That does seem like a match based on the shape of the second row of bumps. I've looked at some other species and those bumps look different on those.

 

Yes, the fossils from these two posts are from the same collection as these nautiloids I posted, which is why I'm guessing Pennsylvanian of Texas or perhaps Kansas (but of course no guarantee that everything from the collection is from the same locality, but many do seem to be):