Recent views on the status, delineation and classification of the Annelida

In recent years the monophyly of the Annelida and Polychaeta has been quest ioned, with various authors proposing that groups such as the Arthropoda, E chiura and Pogonophora render the Annelida and/or Polychaeta paraphyletic. The Clitellata have also been proposed to be a member of the Polychaeta, po tentially making this latter taxon synonymous with the Annelida. The relati onships within the traditionally formulated Polychaeta have never been inve stigated using cladistic methodology. Recent classifications of polychaetes show a large number of "orders" with no real attempts to relate the groups in a phylogenetic sense, In this paper a number of recent studies on annel id systematics and classification are reviewed. Special emphasis is placed on the cladistic parsimony analyses of Rouse and Fauchald (1995, 1997) wher e a comprehensive assessment of the relationships among the various polycha ete and annelid groups was attempted. A contrasting result by Westheide (19 97) using a different methodology, is also outlined and discussed.