• Martin L. Christoffersen
  • Elinei Araújo-de-Almeirda
Palavras-chave: Hennigian systematics, Phylogenetic principles, Additive transformation series, Deuterostome concept, Vertebrate origins, Sistemática Hennigiana, princípios filogenéticos, séries de transformação aditivas, conceito dos deuterostomados, origem dos vertebra


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.