Phylogenetic relationships within the lophophorate lineages (Ectoprocta, Brachiopoda and Phoronida)

Abstract

We produced two new EST datasets of so far uncovered clades of ectoprocts to investigate the phylogenetic relationships within the lophophorate lineages, Ectoprocta, Brachiopoda and Phoronida. Maximum-likelihood analyses based on 78 ribosomal proteins of 62 metazoan taxa support the monophyly of Ectoprocta and a sister group relationship of Phylactolaemata living in freshwater and the mainly marine Gymnolaemata. Hypotheses suggesting that Ectoprocta is diphyletic with phylactolaemates forming a clade with phoronids or paraphyletic with respect to Entoprocta could be rejected by topology tests. The hypotheses that Stenolaemata are the sister group of all other ectoprocts, that Stenolaemata constitutes a monophyletic group with Cheilostomata, and that Phylactolaemata have been derived from Ctenostomata could also be excluded. However, the hypothesis that Phylactolaemata and Stenolaemata form a monophyletic group could not be rejected. Brachiopoda and Phoronida constitute a monophylum, Brachiozoa. The hypotheses that phoronids are the sister group of articulate or inarticulate brachiopods could be rejected by topology tests, thus confirming the monophyly of Brachiopoda.