Article: Crinoid ossicles in Upper Ordovician benthic marine assemblages from Snowdonia, North Wales

Analyses of upper Ordovician (Caradoc) shelly faunas from Snowdonia, North Wales, reveal a remarkable diversity of crinoid columnals. So far, fifty-one columnal morphotypes have been recognized am these are listed, illustrated, and described. The morphotypes are categorized on the basis of earlier schemes of classification. The morphotype diversity implies that the original crinoid faunas were varied. Further applications of the columnal morphotype list include the potential recognition of morphotype combinations which originally comprised hetero- and xenomorphic columns and the possible use of the morphotypes in biostratigraphy.