A cladistic analysis of the anomalocystitid mitrates

A cladistic analysis of the anomalocystitid mitrates is presented. A neutra l terminology for the anomalocystitid skeleton is proposed, independent of the zoological interpretation of the fossils as echinoderms or as craniates . The anomalocystitid monophyly is supported by parsimony, although tie ins tability of several basal taxa makes it difficult to ascertain the sequence in which characters were acquired or modified in the transition from the m itrocystitids to the anomalocystitids. The genus Barrandeocarpus falls outs ide the anomalocystitids as traditionally defined in the literature, and is either polyphyletic or monophyletic. Diamphidiocystis drepanon is either a basal anomalocystitid or the sister taxon to the group (Enoploura popei Allanicytidiidae). Ateleocystites guttenbergensis is placed either at the b ase of the anomalocystitids or as the sister taxon to a group including mai nly boreal forms, the only non-boreal members being the South African Bokke veldia oosthuizeni and the Australian Victoriacystis wilkinsi. (C) 1999 The Linnean Society of London.