Time: Pennsylvanian (~300 m.y.a.)
mm long on a 55 mm by 35 mm nodule
Site: Mazon Creek, Pit 11, Francis Creek shale, Braidwood, Illinois
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 a member of an extinct lobster-like Order that flourished
during the Carboniferous is North America and Europe. The antennae,
antennules, and legs are quite easily discerned in this fine example.