Bite marks and overgrowths on crinoids from the Stramberk-type limestones in Poland

摘要

Various types of bite marks and overgrowths on crinoid ossicles from the Upper Jurassic Stramberk-type limestones of Poland have been described. Echinoid bite marks include small and shallow depressions on the columnal latera, which are elongated perpendicularly or diagonally to the articular surface of the crinoid columnals. On the other hand, crater-shaped indentations, oval in outline, occurring on the crinoid cups, were likely formed by fish predators. The apical overgrowths of columnals were also reported. In contrast to Triassic and Cretaceous crinoids, the overall fequency of predation traces in Jurassic crinoids from the Stramberk-type limestones of Poland is relatively low.