Primitive koa finch Downloaded on 10 July 2007. Primitive koa finch The primitive koa finch ("Rhodacanthis litotes") is a species of Hawaiian honeycreeper. It was endemic to Hawaii. Of the four species in the genus "Rhodacanthis", it and the scissor-billed koa finch became extinct before the arrival of the first Europeans to Hawaii in 1778. It is known as the ancestor of all koa finches. An adult primitive koa finch was slender and had a total length of about . There was probably a small distinct difference between the sexes. Based on fossils, it is known that the adult primitive koa finch had
Acacia koa confirmed this close relationship; the estimated time of divergence is about 1.4 million years ago. "A. heterophylla" sequences nest within those of the more diverse "A. koa", making the latter paraphyletic. Both species are thought to be descended from an ancestral species in Australia, presumably their sister species, "Acacia melanoxylon". Dispersals most likely occurred via seed-carrying by birds such as petrels. Both species have very similar ecological niches, which differ from that of "A. melanoxylon". A closely related species, koaia or koaie ("A. koaia"), is found in dry areas. It is most easily distinguished by having smaller seeds that are