Echinoids (Echinoidea, Echinodermata) from Stramberk-type limestones in Poland

摘要

Echinoid remains recovered from Stramberk-type limestones (Tithonian to Berriasian) in southeast Poland comprise mainly disarticulated corona plates and fragmentary spines. Nevertheless, twelve different taxa could be recognised among the material, most of which could be identified at family or genus level. In addition, eleven types of spines were documented, including at least one additional echinoid group. The fauna is dominated by various cidaroid groups, which account for the bulk of the material. Non-cidaroid echinoids are represented by rare finds belonging to diademataceans, hemicidarids, stomechinids, arbacioids, and phymosomatoids (spines only). Faunal composition is closely similar to that of Oxfordian and Kimmeridgian strata in France and Poland. None of the echinoid taxa identified exclusively occurs in Lower Cretaceous strata, although many of them range into that interval. Echinoid data thus hints at a Late Jurassic age of the assemblage. Test fragments of Tylocidaris sp. found among the material may represent the oldest record of the genus.