Unusual Ammonite

[TyrannosaurusRex]

Hey folks! I’ve got an unusual ammonite found in Rankin Texas. I believe it’s from Edwards Limestone, but I don’t have an exact pinpoint on the location. This whole one was found, and a part of another of the same species, but I haven’t been able to identify them as of yet. 
 

Edit: Confirmed it is indeed Edwards Limestone. 
 

Measurement is with a 1in with centimeters marked. 
Thank you!

Edited March 15, 2022 by TyrannosaurusRex
Confirmation of formation.

[fossisle]

Looks like a Nautilus with ribs on the venter. Not sure which genera are found there

[TyrannosaurusRex]

11 minutes ago, fossisle said:

Looks like a Nautilus with ribs on the venter. Not sure which genera are found there

I did wonder if it could be nautilus. To my knowledge there aren’t any that have been found in that area previously. I couldn’t find any similar specimens at all, but I’ll keep looking. I’m sure they’re out there. Thank you! 

[Harry c]

i dont know much about he USA geology but it looks like either a large nautils or rib bones

[TyrannosaurusRex]

1 hour ago, Harry c said:

i dont know much about he USA geology but it looks like either a large nautils or rib bones

Vertebrate material is not found in Edwards Limestone. It’s a marine deposit that’s limited to oyster beds, ammonites, and the like, so it cannot be ribs.
But thank you for the thought!  
 

 

[Lone Hunter]

This is a nautiloid I found in Trinity river,  believe it's Cymatoceras,  hard to tell if that's what yours is or if it's maybe a Goniatite? 

[TyrannosaurusRex]

10 hours ago, Lone Hunter said:

This is a nautiloid I found in Trinity river,  believe it's Cymatoceras,  hard to tell if that's what yours is or if it's maybe a Goniatite? 

Beautiful nautiloid. The preservation on that piece is very nice, the ribbing is lovely. Thank you for sharing it! It seems nautiloids are very far and few between in Texas.  
 

The problem with it being a Goniatite (and I’ve wondered the same thing) is that they went extinct at the end of the Permian period, and Edwards is mid Cretaceous. Everything else in this deposit is in line with that. It’s a caliche pit, but these were found well within the edwards limestone, some even quite high in the layer. 
 

The most common ammonite I’ve found in the pit is Mortoniceras, some of which are fragments of the species exceeding 15 inches in diameter. The other species recovered was a decently well preserved Engonoceras, potentially serpintinum.

 

Source: USGS.GOV

More located here.

Edited March 15, 2022 by TyrannosaurusRex
Edit to add source and italicize names so I can read them easier

[TyrannosaurusRex]

I went and grabbed the other two examples of whatever this species is. 
 

Broken section

Same ribbing as the complete specimen. 
 

A complete, smaller example of the species. 

[doushantuo]

for those who wonder about such things: Trex's log seems to be lifted straight from a Wikipedia page

[TyrannosaurusRex]

7 hours ago, doushantuo said:

for those who wonder about such things: Trex's log seems to be lifted straight from a Wikipedia page

Thank you, but that in fact, is not true. Perhaps Wikipedia found the same source as I. 

 

The image came from the United States Geological Survey, from a paper called

 

“2003 Geologic Assessment of Undiscovered Conventional Oil
and Gas Resources in the Upper Cretaceous Navarro and Taylor Groups, Western Gulf Province, Texas” 

 

11th page. 
 

Source located here. USGS.GOV

 

Hope this helps. 

[TyrannosaurusRex]

The closest thing I’ve found is Eutrephoceras dekayi, but the ribbing is not quite right. The ribbing is going the other direction and is tighter together. Definitely looks like Nautilus. I’ve gone through the “Texas Cretaceous Ammonites and Nautiloids” and that was the closest thing to it that I was able to find. 
 

[doushantuo]

TREX, JohnJ: Thanks for responding.

So, was I trying to make a point? In hindsight, maybe, subconsciously so.

 

The point I will try to make in this contribution is this: for "Eaglebine"*  stratigraphy, pre-circa 2010 literature is not exactly "suspect, but I would dissuade people from using it.  (* Eagle Ford/Woodbine reservoir plays are continually being(re)examined.)

 

Furthermore, as I have previously hinted at, the Cretaceous of Eastern North America has a complicated stratigraphy.

Edit: Trex: kudos to you for using USGS material.

Another edit: I cast a superficial glance at the "ornamented nautiloid, Cymatoceras neocomiense.

 

 

 

[TyrannosaurusRex]

6 hours ago, doushantuo said:

TREX,JohnJ :thanx for responding.

So: was i trying to make a point?

In hindsight: maybe subconsciously so

The point i will try to make in this contribution is this:

for "Eaglebine" (*)stratigraphy, pre-circa 2010 literature is not exactly "suspect",but I would dissuade people from using it

(* Eagle Ford/Woodbine reservoir plays are continually being(re)examined)

Furthermore,as i have previously hinted at: the Cretaceous of Eastern North America has a complicated stratigraphy

edit: Trex: kudos to you for using usgs material

another edit: i cast a superficial glance at the "ornamented nautiloid "Cymatoceras Neocomiense.

 

 

 

That’s incredibly helpful information, thank you! I’m incredibly new to learning stuff about layers, so thank you for the info. USGS has been an invaluable resource for me finding locations and reading up on information. I’ll see what more I can find. That info you’ve provided is incredibly helpful though, thank you!

[Harry c]

On 3/15/2022 at 2:23 PM, TyrannosaurusRex said:

Vertebrate material is not found in Edwards Limestone. It’s a marine deposit that’s limited to oyster beds, ammonites, and the like, so it cannot be ribs.
But thank you for the thought!  
 

 

good to know

[fifbrindacier]

I'm not an ammonite expert, but i'll try Metengonoceras

http://www.ammonites.fr/Fiches/0707.htm