Esconichthys apopyris
Pennsylvanian
Carbondale Formation
Kankakee Co.
Illinois, USA.

Fossil specimen of Esconichthys apopyris, an extinct ray finned bony fish from the Carbondale Formation of Kankakee County, Illinois. This fossil dates to the Pennsylvanian Subperiod, roughly 307 million years ago, when the region consisted of coastal swamps, river deltas, and shallow brackish waters.
40mm in 55mm paired concretion