DRILL HOLE PREDATION ON FOSSIL SERPULID POLYCHAETES, WITH NEW DATA FROM THE PLIOCENE OF THE NETHERLANDS

The fossil record of drill holes in shelled invertebrates is primarily focused on bivalves and gastropods as prey. I attempt to show by means of an examination of serpulid polychaetes from the Pliocene of Langenboom (The Netherlands) and a review of the literature that drill holes are much more common in fossil tube-bearing serpulid polychaetes than previously known. A study on a population of 915 specimens of Ditrupa cf. arietina shows that >17.4–62.1% of the Langenboom population was drilled. Three methods were used, two of which are new. Drill holes in specimens from Langenboom were primarily formed by naticid gastropods, suggesting that Ditrupa cf. arietina had at least in part an infaunal lifestyle. In general, it appears that Ditrupa spp. and scaphopods are mainly drilled in the middle part of the tube regardless tube length, which suggests that naticids were able to locate the tissue inside the tube when the animal had withdrawn into its tube. Not only does this study address drill hole predation on serpulids through time and their paleogeography, but it also illuminates naticid behavior in selecting a drill hole site on cylindrical tubes.