At a Dry Dredgers meeting, my good friend Rich Fuchs told me he had found one of my mystery fossils in the Geier Collections and Research Center, where he volunteers.
When I arrived there, Rich pulled out the Drawer.....
And sure enough, it was a four-element specimen of the "Mystery Fossil."
I was surprised to find that it had been found in 1966 by a Mr. Jenkins and identified informally in 1972 by Bill Harrison, a well-known Dry Dredger.