I'm new, my 1st attempt to post. Trying to identify this fossil.

[Coxcityok]

 

[Even]

That's a partial cephalon of a Trinucleidae trilobite.

Edited January 17, 2023 by Even

[minnbuckeye]

I am a terrible identifier of trilobites, but I am providing an image that shows a trilobite with a cephalon (head) that would leave an imprint like the one you show us.

 

[Misha]

I agree on trinucleid, in your tags you mention Devonian and Haragan, are you sure this isn't from somewhere else? Trinucleid went extinct at the end of the ordovician 

[piranha]

Four cryptolithines have been described in the Ordovician of southern Oklahoma:

 

Cryptolithoides carinatus
Cryptolithoides fittsi
Cryptolithoides ulrichi
Cryptolithus convexus

 

The posted specimen is a good match with the uniformly small pits of Cryptolithoides ulrichi.

The others have a similar array of large pits illustrated in the figure of Cryptolithus convexus.

 

 

Shaw, F.C. 1991
Viola Group (Ordovician, Oklahoma) Cryptolithinid Trilobites: Biogeography and Taxonomy.
Journal of Paleontology, 65(6):919-935

 

Shaw, F.C., Lespérance, P.J. 1994
North American Biogeography and Taxonomy of Cryptolithus (Trilobita, Ordovician).
Journal of Paleontology, 68(4):808-823

[Coxcityok]

9 hours ago, Misha said:

I agree on trinucleid, in your tags you mention Devonian and Haragan, are you sure this isn't from somewhere else? Trinucleid went extinct at the end of the ordovician 

You are right. Instead, I should have tagged Ordovician age, Viola formation. I will try to edit my post. Thanks!

[Coxcityok]

2 hours ago, piranha said:

Four cryptolithines have been described in the Ordovician of southern Oklahoma:

 

Cryptolithoides carinatus
Cryptolithoides fittsi
Cryptolithoides ulrichi
Cryptolithus convexus

 

The posted specimen is a good match with the uniformly small pits of Cryptolithoides ulrichi.

The others have a similar array of large pits illustrated in the figure of Cryptolithus convexus.

 

 

Shaw, F.C. 1991
Viola Group (Ordovician, Oklahoma) Cryptolithinid Trilobites: Biogeography and Taxonomy.
Journal of Paleontology, 65(6):919-935

 

Shaw, F.C., Lespérance, P.J. 1994
North American Biogeography and Taxonomy of Cryptolithus (Trilobita, Ordovician).
Journal of Paleontology, 68(4):808-823

Thank you!

[Coxcityok]

11 hours ago, Even said:

That's a partial cephalon of a Trinucleidae trilobite.

Thank you.