Hoopoe-billed ʻAkialoa

Hemignathus upupirostris (synonym: Akialoa upupirostris ) is an extinct species of bird in the genus Hemignathus within the subfamily of clothes birds. The specific epithet is derived from the convergent similarity to the lower mandible of a hoopoe (Upupa epops ).

Hemignathus upupirostris was initially known only by subfossiles bone material, which consists of a lower jaw with missing link ends and two Unterkiefersymphysefragmenten. The type localities in which the material was found in 1976, are the Makawehi Dunes on Kauai and Barbers Point on Oahu. In the period following a skull with an upper jaw and a damaged palate bone was unearthed in the Mahaulepu Cave on Kauai. The age of the bone is estimated to be over 6000 years.

An undescribed species, which has similarities with Hemignathus upupirostris in the beak morphology is known from a damaged lower jaw from the island of Maui.

Features

Hemignathus upupirostris has has a very long, thin and curved downward mandible, and the similarities with the mandibles of the latter day extinct Akialoaarten of Oahu, Kauai, Lanai and Hawaii. Of all the other dresses birds to Hemignathus upupirostris differs by the absence of a tongue trough in the mandibular symphysis. This presumably indicates a shorter tongue.