A phylogenetic analysis of higher taxa in the phylum sipuncula

Abstract

Twelve taxonomic characters of the genera in the phylum of marine worms, Sipuncula, are examined and polarities assigned to the various states. A Hypothetical Ancestral Sipunculan is proposed and probable evolutionary pathways are presented. The PHYLIP “Camin-Sokal” and the PAUP “Wagner” parsimony programs are used, as well as Dice's similarity coefficient and UPGMA cluster analysis. These provided both cladistic and a hybrid phenetic/cladistic analyses. Only 5 of the 12 characters are clearly not homoplastic. While monophyly is not demonstrated in all cases, the 17 genera are now grouped into six families, four orders, and two classes as a result of using evolutionary, phenetic, and phylogenetic methodologies. The selective removal of homoplastic characters within the two classes did not significantly alter the composition of the orders or families. The evident congruence among these methods affirms the value of a synthetic approach. © 1985 Society of Systematic Zoology.