Trilobites
Order Phacopida Suborder Calymenina, Superfamily Calymenoidea,
Family Calymenidae
Geologic Age: Middle Silurian
Trilobite is 40 mm long
Niagaran Limestone, Joliet Formation, Grafton, Illinois
Remarks: Coming from the Silurian dolomitic limestone of Grafton, Illinois,
this fossil is an internal cast. Calymene celebra has been assigned
to several different genera over the
past century, includingCalymene, Flexicalymene, Gravicalymene, and
Sthenocalymene. It is the Wisconsin
state fossil. It occurs widely in the midwest of the U.S.
Also see:
American Trilobites
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