Early Cretaceous (Valanginian) sea lilies (Echinodermata, Crinoidea) from Poland

Abstract

Valanginian strata in central epicratonic Poland have recently yielded crinoids, not previously recorded from the area. The fauna comprises isocrinids (Balanocrinus subteres, B. gillieroni, “Isocrinus?” lissajouxi), millericrinids (Apiocrinites sp.) and comatulids (Comatulida indet.). For comparison, a few samples of isocrinids from Valanginian strata of Hungary (Tethyan province) were also analysed. The isocrinids, cyrtocrinids and roveacrinids (sensu Rasmussen 1978 inclusive of Saccocoma sp.) were already known from the Valanginian of the southernmost Tethyan regions of Poland (Pieniny Klippen Belt and Tatra Mountains). The current study demonstrates their occurrence in central epicratonic Poland, and suggests that many Jurassic to Cretaceous stalked crinoid taxa (mainly isocrinids) predominated in the shallow-water settings of this area. Thus, the hypothesis of migration (at least from mid-Cretaceous onwards) to deep-water areas, as a response to an increase of the number of predators during the Mesozoic marine revolution, seems not to be universally applicable.