Proposed subgenera Several
subgenera have been proposed for splitting out of this group. It is becoming clear how the genus might be split up, with a range of
DNA sequence data in large parts agreeing with S.D. Blum's landmark 1988
phylogenetic assessment of
osteology. Basically, a core group around the
type species Chaetodon capistratus would remain in
Chaetodon, while maybe four
clades would be split off. These could use the names
Lepidochaetodon,
Megaprotodon and
Rabdophorus, and there is one unnamed group containing the
three-banded butterflyfish (
C. robustus) and its relatives. But the
monophyly of the
Lepidochaetodon group is not fully established; it is both unclear whether
Rhombochaetodon is a lineage distinct from
Exornator, and whether
Lepidochaetodon is indeed closer to these than to any other
Chaetodon, particularly to some lineages otherwise placed in
Megaprotodon. Historically, more distantly related fish were placed in
Chaetodon too, for resembling them in details – e.g. the
common scat Scatophagus argus, which has a similar shape and size, as well as armored larvae like the Chaetodontidae – or simply because they are colorful, smallish, and unusual-looking – e.g. the quite unrelated
paradise fish, as
C. chinensis. The classification proposed in Fessler and Westneat is based on the species of
Chaetodon they sampled and these sorted into the following clades: == Extant species ==