Unknown nautiloid(?), unfortunately no location or info

[JohnBurrows]

I recently bought this on online with no provenance, from a buyer with 1 feedback and some rubbish photos. 

 

To be honest I figured either nothing would turn up or itd be concrete, which is what I was hoping for  (needed a doorstop) 

 

'Unfortunately', it appears to be real, and now I'm interested. I'd appreciate any input. I've tried to show the shell patterns in some of the photos, as well as other fossils in the matrix base. 

[DPS Ammonite]

You just bought some real fossil doorstops. No idea of what genera they are

[Ludwigia]

I've never seen a nautiloid with ribs like that. I'm thinking that this might be an ammonite like a Cadoceras.

[BobWill]

1 hour ago, Ludwigia said:

I've never seen a nautiloid with ribs like that. I'm thinking that this might be an ammonite like a Cadoceras.

I'm not finding a good match either but I've noticed that some of the Paleozoic nautiloids have more ornamentation than many of the ammonoids from that era which is opposite of what I see in the Cretaceous. I can't really tell if the wavy patterns in the 3rd and 4th picture are sutures or evidence of septa or just random breaks but there are goniatites with sutures that simple and nautiloids with sutures that folded 

 

There are similar umbilical ribs on some species of Tainoceras, Domatoceras and Metacoceras from the Pennsylvanian. Cadoceras certainly fits the deep umbilicus and ribs well though. It makes it frustrating to have no provenance on this one.

 

 

 

Edited August 10, 2022 by BobWill

[Manticocerasman]

I would also tend to a cadicone shaped ammonoid.

[JohnBurrows]

It definitely does have an uncommonly deep centre. Despite there being a ruler literally right there, I forgot to actually apply scale to it - but the mystery lil fella is approx 15cm long and the matrix maybe 23cm. Both together weigh around 1700g.

 

Appreciate the suggestions. I'm going to contact the original seller and see if they have any ideas or vague memories of where it might have come from. 

 

Thank you.