I’ve been walking over this every day

[Interested In Everything]

Hello, first time poster - long time admirer. I moved to a new place and have been walking over this every day while getting exercise. What is it? 

 

KC Group, Middle Zarah Subgroup, Wyandotte Formation, Quindaro; aprox 4cm across at widest.

 

This is in Kansas City, once the fringes of a great inland sea - so shallow marine fossils abound! It is located on the top edge of a natural bluff, enhanced by being an interstate highway cut, and is actually on the floor of an old stone quarry from the 1940’s - hence the probable erosion. At first glance I thought it the thorax of a trilobite, or an impression of one, but as it is the same color as the stone surrounding it, it just doesn’t seem to be right. I could use some knowledgable help. My guess is a ptychodus tooth - but I am way out of my depth here  Thanks

 

Edited May 18, 2020 by Interested In Everything
Clarification of tag, added humor to body.

[Rockwood]

2 hours ago, Interested In Everything said:

My guess is a ptychodus tooth

Perhaps a mold of one ? It appears to be concave, and the texture seems wrong to be an actual tooth.

[TqB]

That really looks like a conulariid. Or possibly a distorted brachiopod fragment.

[FossilNerd]

1 hour ago, TqB said:

That really looks like a conulariid

This was my first thought as well. 

[Interested In Everything]

Thanks for the replies, much appreciated. We’re in the Pennsylvanian strata here in K.C. and I thought that conulariida checked out quite a bit prior. That said, descriptively that does look like an impression of one. Ptychodus ridge counts don’t really match, and the concavity of the whole thing is not right - plus, the ridges seem to be positive and not a cast. It’s not like any fossil I have seen, in terms of color and material. I might examine in further today, see what is around.

 

Thanks again, it just seemed odd - had to ask.

[TqB]

10 minutes ago, Interested In Everything said:

Thanks for the replies, much appreciated. We’re in the Pennsylvanian strata here in K.C. and I thought that conulariida checked out quite a bit prior. That said, descriptively that does look like an impression of one. Ptychodus ridge counts don’t really match, and the concavity of the whole thing is not right - plus, the ridges seem to be positive and not a cast. It’s not like any fossil I have seen, in terms of color and material. I might examine in further today, see what is around.

 

Conulariids are fine in the Pennsylvanian - they made it through to the Triassic. (Ptychodus is Cretaceous anyway...)

[Interested In Everything]

Oh wow, alright - thanks, this is not my field, yet I should have caught that. I did do a fair amount of research, as best I could, but fell asleep covered in wikipedia pages - lol; I can now rest easy. Thanks