SCHWARTZ, M.L.; NORENBURG, J.L.: Can We Infer Heteronemertean Phylogeny from Morphological Data?

A cladistic analysis of the genera within the order Heteronemertea (Nemertea) was performed from morphological data gathered from the literature. Resulting trees were numerous and mostly unresolved. The analysis gives insight into current taxonomic problems for the heteronemerteans. Chief among these are brief and inadequate taxonomic descriptions of species and morphological features. The limited number of characters and poor definition of homologies available in this literature-based data set result in abundant homoplasy and hinder progress towards building a robust phylogeny for the Heteronemertea. To remedy this, we are undertaking a critical re-examination of taxa and characters by direct study of a range of heteronemertean exemplar species, for which we are gathering molecular sequence data to complement the morphological data. We expect the resulting analyses to alter drastically the face of heteronemertean systematics.