Most biologists are familiar only with a few of the approximately 40 extant animal phyla. The purpose of this symposium was to renew interest in the lesser-known invertebrate taxa, encourage their use in research and teaching and to promote the relevance of high-level systematic studies. This paper reviews the two major views of metazoan evolutionary relationships with particular attention to the lesser-known taxa and to some of the new and/or conflicting terminology used in current animal phylogenetic study. The current use of lesser-known taxa in research is briefly described, and the discussion that followed the symposium is summarized. The paper concludes with a brief history of the symposium and a tribute to Robert P. Higgins, who organized three "Symposia on the Lesser-Known Invertebrates" over the past 25 yr.