The fact that
Proapteryx lacked specialisation for a terrestrial, flightless lifestyle supports the hypothesis that kiwi ancestors flew to New Zealand from
Australia in the Miocene, well after
moas had developed their modern forms – moa remains are also known from Saint Bathans, already large and flightless. This supports genetic and morphological analyses indicating that the two clades arrived in New Zealand independently and are not particularly closely related, moas forming a clade with
tinamous, and kiwi with Australian
ratites, the
cassowary and
emu. Kiwi have also been found by molecular studies to be the sister taxa of the
elephant birds of
Madagascar.
Proapteryx establishes the existence of flying Australian
palaeognaths as recently as the early Miocene, indicating that the
Malagasy ratites may have flown across the Indian Ocean around this time. ==References==