PHYLOGENETIC ANALYSIS OF HIGHER TAXA OF BRACHIOPODA

Inferred phylogenetic relationships within the Brachiopoda have long b een accepted as demonstrating repeated transitions from a phosphatic s hell chemistry to a calcareous composition. This interpretation is ref lected in the major subdivision of the phylum into the classes Inartic ulata and Articulata. Cladistic analysis suggests, however, that the p hosphatic-shelled and the calcareous-shelled Brachiopoda are sister gr oups that have had consistently separated shell chemistries from early in phylogenetic history. This separation is recognized in the class-r ank divisions Lingulata and Calciata, the former of which includes the new Subclass Lingulatea, whilst the latter includes the new Subclass Craniformea together with the 'articulates' of previous classification s.