Bizarre Amynilyspes Mazon Creek Pill Millipede Fossil

Description: The Mazon Creek deposits of the region near Braidwood, Illinois rival the other famous Lagerstatten of the Burgess Shale, Solnhofen, and Liaoning for the variety of detailed life preserved. Many exquisitely-preserved specimens are found in the ironstone nodules that make up the deposits. The majority of collecting areas are the spoil heaps of abandoned coal mines, the most famous of which is Peabody Coal Pit 11. Pit 11 now serves as a cooling pond for the Braidwood nuclear power plant, but with over 100 other localities, specimens still come to light.

This specimen is of a group not commonly seen from the Mazon Creek fauna known as Amynilyspes, a pill millipede. In addition to the pill millipedes, the Mazon Creek Fauna also has members of the euphoberids and the xyloiulids. The pill millipedes have the capacity to coil into a ball so tightly that they can be watertight when fully enrolled. The pill millipedes persist to the present day, and are associated with the forest floor. Note that this specimen has fronds of the fern Pecopteris in association.