Devonian
Catskill Formation
Sherman Creek, PA, USA
121mm near complete placoderm with one paddle on 300mm slab with scales of the coelacanth Holoptychius
Fish, Placoderm.

Bothriolepis is a genus within the Class Placodermi, a group of diverse armored fishes that ruled the Devonian seas.  Its remains have been collected from every continent including Antarctica.  It has been a poster child for placoderms as it is commonly-illustrated in mainstream science books covering fossil fishes and in trading cards and stamps.

Bothriolepis specimens were once a common sight at mineral/fossil shows but the Canadian government shut down exports a long time ago.  Here’s a nice association piece with coelacanth scales for the fish collector who wants an atypical example of a classic extinct fish.