Cyclus americanus
Class Crustacea, Order Maxillipoda
Geological Time: Pennsylvanian (~300 m.y.a.)
Size (25.4mm=1 inch): Fossil is 18 mm long, 10 mm across, Matrix: 32 mm by 45 mm
Fossil Site: Mazon Creek - Francis Creek Shale, Braidwood, Illinois
Code: CB13
Price: $25.00
 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. The taxonomy of these animals has been under dispute ever
since their discovery in the late 1800s; they are currently thought
to have the copepods as nearest relatives. They have been thought
to have possibly parasitized fish, but their association with plant
matter seems to indicate habits more like the crabs. Usually, only
the shell is preserved, but here the long antennae can just be made
out. |
