Pseudozygopleura species?

[Ruger9a]

Good evening folks.  I have an item from the back of my "unidentified" drawer that I originally thought was a Pseudozygopleura species.  I am having doubts because of the "twist" of the shell going 180 degrees in the opposite direction.  Any help is appreciated. 

[DPS Ammonite]

Consider that it might be a “Turrilites” ammonite. These Cretaceous ammonites probably occur in Georgia rocks.

 

 

[FossilDAWG]

Where is this from?

Turrilites is not known from Georgia or Alabama as fossiliferous marine Albian or Aptian rocks are not present.  However Nostoceras does occur very rarely in the Ripley Formation (late Campanian or early Maastrichtian), and the turret part is much like Turrilites.  That being said I don't see any suture lines.

 

Don

[Ruger9a]

Thank you!  I was definitely looking at the wrong species.  It does resemble a well worn Turrilites costatus.

[Ruger9a]

Just now, FossilDAWG said:

Where is this from?

Turrilites is not known from Georgia or Alabama as fossiliferous marine Albian or Aptian rocks are not present.  However Nostoceras does occur very rarely in the Ripley Formation (late Campanian or early Maastrichtian), and the turret part is much like Turrilites.  That being said I don't see any suture lines.

 

Don

Don, sorry, it was a purchase from one of the sellers in the 100 mile annual Georgia/Florida yard sale.  I was with several other items without an identification tag, just listed as garden rocks.  So, I don't actually know where it came from or was originally found.

[BobWill]

Without provenance it may be hard to assign a species name or even a genus since there is also the possibility of it being a Mariella. There are several species of each we find in Texas and the differences can be very subtle.

Like members of the Nostoceratidae family Don mentioned, the Mariellas generally have a larger apical angle than Turrilites but the latter not quite as obtuse as the former. Yours seems a little larger angle than most Turrilites but there is some overlap for that character. Many other features can also vary widely like the size,  shape and number of rows of tubercles and the sutures which I seldom see in my samples

If having it right is important you may just want to label it "Cretaceous Heteromorph Ammonite."

[Ruger9a]

Thank you Bob.  I guess I still have additional research to perform to "hopefully" pin it down.  All three species are beginning to look the same to me right now.

[FossilDAWG]

I answered your PM before I saw the latest contributions to this thread.

 

There are a number of Cretaceous heteromorphic ammonite genera that have this general turrited shape.  They can be distinguished by the degree to which whorls are in contact, by ornament (ribs, nodes, spines), and by the shape of the living chamber.  In Didymoceras and Nostoceras the living chamber forms a hook like shape below the phragmocone.  In Turrilites and Mariella the living chamber is part of the turret.  Without convincing locality/formation/age data and lacking the living chamber I would be reluctant to ID this specimen t to a particular genus.

 

Don

[Ruger9a]

On 4/9/2020 at 11:08 PM, FossilDAWG said:

I answered your PM before I saw the latest contributions to this thread.

 

There are a number of Cretaceous heteromorphic ammonite genera that have this general turrited shape.  They can be distinguished by the degree to which whorls are in contact, by ornament (ribs, nodes, spines), and by the shape of the living chamber.  In Didymoceras and Nostoceras the living chamber forms a hook like shape below the phragmocone.  In Turrilites and Mariella the living chamber is part of the turret.  Without convincing locality/formation/age data and lacking the living chamber I would be reluctant to ID this specimen t to a particular genus.

 

Don

Thanks Don.