A PHYLOGENETIC FRAMEWORK OF THE ENTEROCOELA (METAMERIA: COELOMATA)

Resumo

The zoological treatise by Hyman represents the culmination of a century-old effort to produce broad morphological syntheses and intuitive phylogenetic trees. We do not entirely accept the present trend to value molecular phylogeny and numerical cladistics at the expense of a more intuitive Hennigian approach of phylogenetic reconstruction. Our main intention here has been to point out some simple and rather neglected ways of doing phylogenetics. We propose a scenariolike narrative of character transformations, from the tubicolous annelids to the vertebrates. The tubicolous annelid taxon Oweniidae is considered the sister group of the Enterocoela. Our main conclusions are that: (1) Chaetognatha represents the sister group of the Vertebrata, within a taxon Bioculata, nov.; (2) tunicates are closer to the Bioculata than the cephalochordates, forming withthe Bioculata the taxon Cephalata, nov.; (3) calcichordates with echinoderm-like skeletons may belong strictly to the stem lineage of the Eupharyngotremata, nov.; (4) "Hemichordata" is a polyphyletic taxon, with enteropneusts, rather than echinoderms, being more closely related to thechordates; (5) "Pterobranchia" is paraphyletic, rhabdopleurids being more basal than cephalodiscids; (6) "Lophophorata" is also paraphyletic, with Phoronida being excluded from the Deuterostomata, whereas Ectoprocta is the more apical sister group of the Pharyngocoela, nov.;(7) the latter two groups are placed within the Coloniata, nov.; (8) Pogonophora, including the Vestimentifera, is the sister group of the Radialia and both groups belong to the Enterocoela.