I discovered these two rollers in Fayette County , Iowa in the lower Maquoketa, Ordovician. This location is well known for Anatophrus borreaus trilobites. Though the next lower formation changes abruptly to almost 100% Isotelus. Did I find one of each? Rollers make IDs tough on me.
Then as long as you "trilo" experts are looking, can you ID the trilo-bits 1,2 and 3 in the next picture? Thanks for helping!!