Cottowood Mbr, Beattie Fm, Council Grove group, Permian. Western Greenwood County, Flint Hills, Kansas.
I've found 6 of these in only in this one place. They are most likely the interior molds of the actual trace. They were discovered over a period of several months. They were found as tumbled out, not in situ.
I'm inferring what's top and bottom due to some obvious features and basic physics.
Some retain what appears to be an original edge around the top. The top diameters range in size from 5" to 10+", with heights from 2" to 6".
These were found in an area disturbed by oilfield work where it looks bulldozed out for some purpose. Geologically, the area may have intermittently been shallow or shoreline. I've done an amateur's inventory of fossils in the immediate area and found highest numbers are of very! small bivalves.