Many organisms were transferred to this genus, and most
Monas spp. have later been synonymised with or integrated in other genera. The organisms once affiliated with
Monas spp. truly belong to all major eukaryotic lineages (
Opisthokonta,
Amoebozoa,
Rhizaria,
Archaeplastida,
Stramenopiles,
Alveolata,
Cryptophyta,
Excavata), and even to prokaryotic lineages. The genus was also included in other groups, as in
Mastigophora or
Flagellata. The current practice is the (questionable) synonymous use, based on morphological similarity, of the generic names
Monas (mostly used in the east-Asian literature) and
Spumella (synonymously used in the European and American literature) as unpigmented biflagellates in
Chrysophyceae. However, there is a conflict between the morphological and molecular investigations. The present-day taxon
Monas/
Spumella is still
polyphyletic, comprising at least three to five lineages, and evidence about the identity of the
type species of
Monas is missing. like other flagellates (e.g.,
Bodo,
Cercomonas) ==References==