SIGNS OF BENTHIC PREDATION ON LATE JURASSIC STALKED CRINOIDS, PRELIMINARY DATA

Abstract

Although most investigations of crinoid-predator interactions have focused on nektonic vertebrates (fishes and sharks), slow-moving benthic animals such as cidaroid echinoids may also interact antagonistically with stalked crinoids. This was recently supported by observations of extant isocrinids in modern deep-sea environments near the west end of Grand Bahama Island. In this paper, we report on stalks of crinoids from the Late Jurassic of south-central Poland, which co-occur with remains of cidaroids and show characteristic holes, bite marks, and signs of breakage. By analogy with the modern example, we interpret this as evidence of predation by cidaroids on crinoids. These Late Jurassic data may indicate that benthic predation was intense during the mid-Mesozoic. Importantly, this discovery also strengthens the hypothesis that benthic predators may have exerted considerable influence on the evolution of stalked crinoids.