In need of help

[Phelsuma82]

I found this on the banks of the Mississippi River in Illinois. So I don’t know where it originated. So I can’t help with age or formation or even a general location. I posted on a couple fossil pages on Facebook and going to try here. Any help will be great. Rough size is in pictures but they are 7.93 mm wide and 6.31 mm tall roughly. If you have questions I’ll try to answer them the best I can. Thank you

 

 

[teotwawki78]

[teotwawki78]

I was just doing a little research and literally just read this about Ostracods, then I saw your pics and thought maybe that is what you have! 

[Phelsuma82]

I will look into those. Thank you for your input.

[pefty]

Maybe it's just a front-ish view of the glabella of a particularly convex trilobite? That would explain the texture and the basal flange, at least...