Pennsylvanian (Missourian)
Stark Shale
Hansen Quarry, La Platte, NE, USA
60mm arthropod in 95mm black shale.

Arthropod. Crustacean.

Gorgonophontes is a genus of crustacean known from a few Late Carboniferous sites in the American Midwest and has been interpreted as a deepwater “proto-mantis shrimp” by a few researchers.  It apparently died out around the beginning of the Permian.

Nicely presented on matrix.