Scolecondont fossil that appears to be a Cornugenys (Jansonius & Craig, 1971). Image taken under microscope and field of view is 2 mm. Found near Brookville Lake, Indiana and Waynesville Formation dates to the Ordovician Period.
Learn more at the Dry Dredgers site: http://drydredgers.org/scolec2.htm
Thanks to Kenny for the image.