THE IDENTITY AND COMPOSITION OF THE EUGLENOZOA

The taxon Euglenozoa was originally created to include the kinetoplast ids and euglenids only. Subsequently, euglenozoan identity and/or affi nities have been suggested for Diplonema, Stephanopogon, the Hemimasti gophora and several even more poorly understood eukaryotes. The Euglen ozoa have only ever been defined by circumscription and/or composition ; attributes that change as taxa are added or removed. This paper seek s to refine and stabilise the concept of the Euglenozoa by redefining it as a clade identified by synapomorphy. It is proposed that the Eugl enozoa be identified by the character 'heteromorphic (tubular and para llel) lattice paraxonemal rods'. Applying this definition, the Eugleno zoa currently consists of four subgroups; euglenids, kinetoplastids, d iplonemids (i.e. Diplonema and Rhynchopus) and Postgaardi. The reasons for the exclusion of Stephanopogon and the Hemimastigophora are also presented.