Drill holes and shell repair in brachiopods from a Late Cretaceous (Maastrichtian) oyster reef, North Canterbury, New Zealand

• Brachiopods in a Late Cretaceous oyster reef were affected by one or more drilling organisms.
• Of five species of brachiopods, only one was significantly affected by drilling.
• Identity of the drilling organisms remains unknown.
• A small number of specimens show repairs to the shell following unsuccessful attack by a grasping/crushing predator.

Several hundred brachiopods were separated from a bulk sample taken from a single locality of the Late Cretaceous Ostrea Bed at the top of the Broken River Formation in the Weka Pass area of North Canterbury, New Zealand. The specimens were divided among five different species and examined for drill holes and shell repair following failed predatory attacks. The results show that one or more unknown predators and/or parasites apparently selectively preyed on the rhynchonellide Wekarhynchia cataracta, with approximately 16.2% of complete shells showing evidence of attack. The larger, coarsely-ribbed terebratulide Ostreathyris allani was seemingly immune to drilling, while sample sizes for the three other brachiopod species were too small to allow even rudimentary estimates of predation/parasitism rates.