Further revisions of the Sabellidae subfamilies and cladistic relationships among the Fabriciinae (Annelida: Polychaeta)

Cladistic relationships of the sabellid subfamilies Fabriciinae and Sabellinae are examined in light of recent revisions of fabriciin taxa. The potential placement of Caobangia in the Sabellinae is suggested from an initial analysis of selected fabriciin species and genera. Subsequent cladistic analyses at the family level produced over 1800 cladograms, among which Caobangia is the most plesiomorphic taxon of either the Fabriciinae or Sabellinae. Successive approximations weighting reduced this ambiguity, consistently placing Caobangia in the Sabellinae. Subfamilies are emended on the basis of these results. Cladistic relationships of fabriciin taxa, exclusive of Caobangia , display topological instability among some genera and species. Genera are, however, monophyletic in all topologies. Incorporating ontogenetic data for branching ventral filamentous appendages in Augeneriella reduces ambiguity among genera and suggests alternative transformation series for ventral filamentous appendages.