Recent Insights into Cnidarian Phylogeny

Abstract

With representatives of more than 10,000 species from diverse clades scattered throughout the world’s oceans, Cnidaria is a moderately diverse phylum of Metazoa. As such, various taxa within Cnidaria have been the subjects of recent phylogenetic analyses. Because of its diversity, it has not yet been possible to conduct any extensive phylum-level phylogenetic analyses. In addition, new information suggests that the large group of parasites known as Myxozoa is part of Cnidaria. The present contribution summarizes recent fi ndings to create a picture of a current working hypothesis of cnidarian phylogeny. This summary, which treats the relationships among taxa down to the approximate level of order, likely provides a suboptimal estimation of cnidarian phylogeny as compared to a detailed phylogenetic analysis of data sampled densely from all the Cnidaria component clades. Nevertheless, it should provide points of comparison for upcoming efforts to more comprehensively assess cnidarian phylogeny. Even at the basic level of order, many taxa are thought to be polyphyletic. Understandably, current classifications are not fully reflective of recent phylogenetic advances.