Disease and trauma in Jurassic invertebrate animals of Poland – an updated review

Abstract

The parasitism of, and predation upon, the diverse Middle and Late Jurassic invertebrates of Poland, personally recognised by the authors, are reviewed. All cases are discussed either in the biological (anatomical, ethological), or ecological terms, to show the mode of infection, or injury, and the relationship between the engaged taxa. The preys to parasites are exemplified by the prosopid crabs infested by bopyrid isopods, the crinoids infested by myzostomid polychaetes (both disk-shaped, and wormlike), and the echinoids attacked by copepod arthropods involving either swellings of spines, or gall-shaped cysts upon the test outerly. Of traumatic events, discussed is regeneration of injuries in the belemnite hooked guards, and in the ammonite shells of distorted ribbing. The pearl-like structures in belemnite guards (the “[i]belemnite pearls[/i]”) are interpreted as caused by a tiny parasite encapsulated during further growth of the belemnite. Heaps of ammonite shell hash are thought to represent the “[i]kitchen middens[/i]” of a larger predator which has feasted upon the fleshy tidbits alone, the beaten shell having been left. The post mortem damage of shells is remarked (taphonomic feedback and/or aftermath) to be distinguished from that one acted in shells of alive specimens of the Middle and Late Jurassic of Poland.