Cytoskeletal organization, phylogenetic affinities and systematics in the contentious taxon Excavata (Eukaryota)

Int J Syst Evol Microbiol. 2003 Nov;53(Pt 6):1759-77. doi: 10.1099/ijs.0.02578-0.

Abstract

An overview of the controversial proposal for the major eukaryote taxon "Excavata" is presented. Excavata is predicted to include at least ten distinct groups: jakobids, Malawimonas, Trimastix, Carpediemonas, retortamonads, diplomonads, Heterolobosea, oxymonads, parabasalids and Euglenozoa. These "excavates" have broadly similar flagellar apparatus organizations, for which a "universal" terminology is provided. Most, but not all, of these organisms share a distinctive suspension-feeding groove, as well as some or all of a set of seven other proposed cytoskeletal apomorphies. Cladistic analyses of morphological data do not resolve high-level relationships within Excavata. Excavate-rich molecular phylogenies recover some robust clades, but do not support or strongly refute the monophyly of Excavata. A partial classification for excavates is presented, with phylogenetic diagnoses for Excavata and for two novel taxon names, Fornicata (Carpediemonas, retortamonads, diplomonads) and Preaxostyla (Trimastix, oxymonads).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amoebida / classification*
  • Animals
  • Cytoskeleton / ultrastructure*
  • Eukaryota / classification*
  • Flagella / ultrastructure
  • Microscopy, Electron
  • Paleontology
  • Phylogeny*