Oichnus simplex Bromley infesting Hemipneustes striatoradiatus (Leske) (Echinoidea) from the Maastrichtian type area (Upper Cretaceous, The Netherlands)

The large holasteroid echinoid Hemipneustes striatoradiatus (Leske) was exploited by diverse invertebrate encrusters and borers during the Maastrichtian, both pre- and post-mortem. In life, the specimen described herein was perforated by multiple Oichnus simplex Bromley borings close to the apical system. Each engendered a growth reaction from the echinoid, a mound-like swelling on the external surface of the test with the boring at the centre....