comparison of mtdna cytochrome "b" sequences found that five species of "phyllastrephus" did not belong to the bulbuls, but to an enigmatic group of songbirds from madagascar instead (cibois "et al.", 2001; see below for the species in question), and they are now usually referred to as malagasy warblers. similarly, sequence analysis of the ndna rag1 and rag2 genes suggests that the genus "nicator" is not a bulbul either (beresford "et al.", 2005). that the previous arrangement had failed to take into account biogeography was indicated by the study of pasquet "et al." (2001) who demonstrated the genus "criniger" must be divided into an african and an asian ("alophoixus") lineage. using analysis of one ndna and 2 mtdna sequences, moyle & marks (2006) found one largely asian lineage and one african group of greenbuls and bristlebills; the golden greenbul seemes to be very distinct and form a group of its own. some taxa are not monophyletic, and more research is necessary to determine relationships within the larger genera.