Ammonite

[Ptychodus04]

Somewhere, I posted about the receipt of this ammonite from @RJB‘s cast off pile. I finished up the prep yesterday. Unfortunately, I don’t know these ammonites well enough to give it a good ID. I know there’s someone here who does though.  I gave up on the back ammonite as its quality wasn’t worth my time.

 

[Ludwigia]

I think it's a Jeletzkyites, but don't quote me on that, cos it might also be a Discoscaphites or a Hoploscaphites.

[Sagebrush Steve]

2 hours ago, Ludwigia said:

I think it's a Jeletzkyites, but don't quote me on that, cos it might also be a Discoscaphites or a Hoploscaphites.

Well,if you want to try to figure it out, you can try reading this paper.  But don’t ask for my help interpreting it, it’s beyond my pay grade. 

660205.pdf

[Ptychodus04]

I would much rather have someone tell me what it is. 

[Ludwigia]

6 hours ago, Ptychodus04 said:

I would much rather have someone tell me what it is. 

Thing is, it's missing out on a few scructural indicators. If it appears to have remnants of spoon-shaped spines on its keel, the you've prolly got a J., since the row of spines on the inner venter point to that. If it has a double row of spikes on the keel, it's either H. or D., although by D. the rows continue over onto the venter more than by H.

[ynot]

11 hours ago, Ptychodus04 said:

I would much rather have someone tell me what it is.

It is a shelled squid!

[RJB]

13 minutes ago, ynot said:

It is a shelled squid!

 Ha!!!   Good one!!!

 

RB

[RJB]

@Ptychodus04  Hi Kris, I just got off the phone with my ammo buddy.   That ammo you have is Hoploscaphites plenus.   Its a female of the species, comes from the Pierre Shale and is 71.5 million years old. 

 

RB

[Sagebrush Steve]

14 hours ago, Ptychodus04 said:

I would much rather have someone tell me what it is. 

 

35 minutes ago, RJB said:

@Ptychodus04  Hi Kris, I just got off the phone with my ammo buddy.   That ammo you have is Hoploscaphites plenus.   Its a female of the species, comes from the Pierre Shale and is 71.5 million years old. 

 

RB

Looks like you got your wish.  Now that you know what it is, your homework assignment is to justify that identification by reading through the paper I posted above and telling us which of the diagnostic features described there justify it.   I’ll expect your paper to be submitted by Thursday. Merry Christmas!

[Ptychodus04]

Thanks @RJB. @Sagebrush Steve, I had my paper finished but my dog ate it.