Abstract

A cladistic analysis of the anomalocystitid mitrates is presented. A neutral terminology for
the anornalocystitid skeleton is proposed, independent of the zoological interpretation of the fossils as echinoderms or as craniates. The anomalocystitid monophyly is supported by parsimony, although the instability of several basal taxa makes it difficult to ascertain the sequence in which characters were acquired or modified in the transition from the mitrocystitids to the anomalocystitids. The genus Barrandeocaqus falls outside the anomalocystitids as traditionally defined in the literature, and is either polyphyletic or monophyletic. Ihamphidiocystk drepanon is either a basal anomalocystitid or the sister taxon to the group (Enoploura pope; + Allanicytidiidae). Ateleocystites guttenbergensis is placed either at the base of the anomalocystitids or as the sister taxon to a group including mainly boreal forms, the only non-boreal members being thc South African Bokkeveldia oosthuizeni and the Australian Pictoriacystis wilkinsi.