Holzmaden/Ohmden Fossil ID

[triplefacepalm]

Hey everybody!

I had an opportunity to visit the Holzmaden area (fantastic museum) and split some rocks at Schieferbruch Kromer in Germany. There were plenty of ammonites and I even managed a few neat belemnite pieces I'm very happy about. But one find has me a bit stumped. It appears to be very thin, and I have the feeling it is some part of an ammonite but I have no clue where it would fit in since it isn't very spirally. The caliper scale for reference is in mm and inches (it's about an inch long). The last 2 photos are at an angle to show some of the relief. If you've got any suggestions, I'd be happy to hear them, thanks!

[Fossildude19]

Looks like part of a bivalve/oyster shell to me. 

[Abstraktum]

@belemniten

[belemniten]

11 minutes ago, Fossildude19 said:

Looks like part of a bivalve/oyster shell to me. 

Agree. Did you took any pictures of the site?

[ricardo]

Radulopecten sp. (?)

[triplefacepalm]

7 minutes ago, belemniten said:

Agree. Did you took any pictures of the site?

No, unfortunately I didn't. It was mixed up with everything else at the surface so I have no idea where in the quarry it was originally.

[Plantguy]

5 hours ago, belemniten said:

Agree. Did you took any pictures of the site?

Thats kind of cool.

@belemniten

I have  a question about aptychii and ribbing that pops in my brain...Do they occasionally have ribbing that runs their length? I havent seen enough of them in hand and was wondering.

The reason I ask is that I was looking at one of the pics of this unknown and rotated it and the lower edge where I placed an arrow seems to show this almost unbroken/clean? vertical edge that appears to gradually curve to the left. When I draw a vertical line up from that edge my brain wants to turn this into an aptychus with its 2 valves. I suppose it could actually be just an actual bivalve with that symmentry but I wonder if further prep might expose more of its outline and make the answer any clearer..?. 

 

Regards, Chris 

[belemniten]

Sorry @Plantguy I forgot to answer 

I think you are right with aptychus. They are very common there as ammonites are very common there too. 

 

On 23.8.2019 at 4:08 AM, Plantguy said:

Thats kind of cool.

@belemniten

I have  a question about aptychii and ribbing that pops in my brain...Do they occasionally have ribbing that runs their length? I havent seen enough of them in hand and was wondering.

Yeah the ones from Holzmaden have occasionally one "rib". I can take a picture of one of mine tomorrow. 

[triplefacepalm]

Thanks for the help everybody! I think @Plantguy is correct about it being an aptychus, it seems to match some other example photos I found after a bit of searching. I've never heard of an aptychus before, so I find this very interesting and have been reading up on it!

On 8/23/2019 at 4:08 AM, Plantguy said:

I wonder if further prep might expose more of its outline and make the answer any clearer.

Unfortunately, there's not much more to expose since it looks like it's sitting on top of the rock. All the edges can be seen and there's no more matrix to remove from what I can tell.

 

Thanks again for teaching me something new!