Fish Part, Fish Tooth, Trilobite Free Cheek?

[cngodles]

Hello all.

 

Quite a time back I found this shiny black thing in a piece of Brush Creek limestone. I had tentatively identified it as a trilobite free cheek part. However, a trip to the museum has the invertebrate paleontology department telling me that it's not for two reasons.

 

1. While similar looking as a free cheek, the top portion doesn't match
2. It's way too big to be a trilobite from this time period.

 

I do agree with both assessments. It's twice the size of a typical Kasimovian (Late Pennsylvanian) trilobite from here.

 

So, any fish part or tooth experts here? Perhaps this matches something that someone has seen. The connection at the junction where it turns into a point is interesting to me.

 

 

Much more detail:

 

[piranha]

35 minutes ago, cngodles said:

1. While similar looking as a free cheek, the top portion doesn't match
2. It's way too big to be a trilobite from this time period.

I do agree with both assessments. It's twice the size of a typical Kasimovian (Late Pennsylvanian) trilobite from here.

 

Unequivocally a trilobite. Carboniferous trilobites could easily attain this larger size.

[cngodles]

10 minutes ago, piranha said:

 

Unequivocally a trilobite. Carboniferous trilobites could easily attain this larger size.

 

I fully respect the assessment on morphology. To note, we are very late Carboniferous where I am at. There is a measurable shrinking even across the formation I'm in. See the reference below. I do not believe the free cheek would fit any of their illustrated examples. So at best, this is quite the odd ball.

 

However, my rocks are odd at best. I've found lots of large things. Elongated Wilkinga. Very large cephalopod pieces. A gastropod that is very big in comparison to all others I've found.

 

Brezinski, D.K., Sturgeon, M.T., Hoare, R.D., 1989, Pennsylvanian Trilobites of Ohio, Report on Investigations No. 142