Ctenobactrites isogramma

Ctenobactrites is a genus of cephalopod under the order of Bactritida, an order rarely found in Western Pennsylvanian rocks. Ctenobactrites differs from Bactrites only by having a coarse transverse lirae (Mapes 1979). While I have found these intact, I have yet to find a suitable steinkern for collection. This specimenRead More →