Aesopichthys erinaceus
Late Mississippian
Bear Gulch Limestone
Fergus County, Montana, USA

Rare 86mm fish on 83mm slab only described since 2000. First we have ever had.

see: Poplin C., Lund R. (2000) Two new deep-bodied palaeoniscoid actinopterygians from Bear Gulch (Montana, USA, Lower Carboniferous), Journal of Vertebrate Paleontology 20 3, 428-449