Parasitism, abnormal growth and predation on Cretaceous echinoids from Egypt

Forty Cretaceous echinoid specimens from Egypt show signs of parasitism, abnormal growth, and/or predation. Many specimens display some deformations such as boring, test bulging, test deepening, and abnormal poring indicating that they have been infested during their lives by parasites. The type of parasite, the relationship between the parasite and the infested echinoids, and duration of attachment are also discussed. Nine types of abnormal growth can be distinguished and described and the causative agents are discussed. Two types of predation-produced deformations are described: boring and partial test damage. The bores are restricted to the adapical surface of Hemiaster spp. This indicates that the attacks occurred during the presence of the echinoids in their burrows.