Petrocrania scabiosa brachiopods (circular) on a Rafinesquina brachiopod, along with a trepostome bryozoan that encrusted some brachiopods and grew around others. The P. scabiosa on the far left shows xenomorphic features.
Wooster’s Fossil of the Week: Encrusting craniid brachiopods (Upper Ordovician of southeastern Indiana)