Probable predatory borings in late Cretaceous bryozoans

Borings are described in zooids of Cenomanian to Campanian melicerititids, an aberrant group of cyclostome bryozoans with calcified opercula. The borings are circular or elliptical, straight-sided and have a diameter of 40–90 μn. Autozooids were drilled in preference to heterozooids and most borings penetrate the operculum. The shape and distribution of boreholes suggests that they were made by a predator attacking one zooid at a time. The predator responsible may have been a gastropod, most probably a nudibranch or a micromorphic muricid. Bryozoa, Gastropoda, predation, borings, Upper Cretaceous.