Genus
Pseudhymenochirus has also been placed as a
subgenus in
Hymenochirus (
African dwarf frogs), although it is geographically widely separated from that genus. At any rate, these two genera are probably
sister groups. In most species in the family Pipidae, sound production occurs without externally visible movements of the flanks or throat and is based on a different mechanism than in anurans in general. This is interpreted as an adaptation to their aquatic lifestyle. However, within pipids,
Hymenochirus appears to be an exception, and sound production is based on moving air in a more conventional anuran manner. Nevertheless, molecular and morphological analyses show that sound production in
Hymenochirus is an evolutionary novelty that represents a reversal to the ancestral condition of air-driven sound production. ==Habitat and conservation==