The Maui Nui large-billed moa-nalo (''Thambetochen chauliodous''), also known as the Maui Nui moa-nalo, is one of two species of

moa-nalo The moa-nalo are a group of extinct aberrant, goose-like ducks that lived on the larger Hawaiian Islands, except Hawaii (island), Hawaii itself, in the Pacific. They were the major herbivores on most of these islands until they became extinct a ...

in the genus ''

Thambetochen Thambetochen is an extinct genus of moa-nalo duck. It contains two species, the Maui Nui moa-nalo (''T. chauliodous'') and the smaller O'ahu moa-nalo (''T. xanion''). The former was found on Maui and Molokai on Hawaii, the latter was found ...

''. Moa-nalo are a group of

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

flightless Flightless birds are birds that cannot fly, as they have, through evolution, lost the ability to. There are over 60 extant species, including the well-known ratites ( ostriches, emus, cassowaries, rheas, and kiwis) and penguins. The smal ...

, large goose-like

duck Duck is the common name for numerous species of waterfowl in the family (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfam ...

s, which

evolved Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

in the

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

of the

North Pacific Ocean North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' ...

Distribution and habitat

The genus and species were originally described in 1976 from

subfossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

material collected from the Moomomi Dunes, on the island of

Molokai Molokai or Molokai ( or ; Molokaʻi dialect: Morotaʻi ) is the fifth most populated of the eight major islands that make up the Hawaiian Islands archipelago in the middle of the Pacific Ocean. It is 38 by 10 miles (61 by 16 km) at its g ...

. Remains of the bird have also been recovered from Ilio Point on Molokai as well as from

lava tube A lava tube, more rarely called a pyroduct, is a 'roofed conduit through which molten lava travels away from its vent'. If lava in the tube drains out, it will leave an empty cave. Lava tubes are common in low-viscosity volcanic systems. La ...

s on the southern slopes of the volcanic mountain of

Haleakalā Haleakalā (; Hawaiian: ), or the East Maui Volcano, is a massive, active shield volcano that forms more than 75% of the Hawaiian Islands, Hawaiian Island of Maui. The western 25% of the island is formed by another volcano, Mauna Kahalawai, als ...

on the nearby island of

Maui Maui (; Hawaiian language, Hawaiian: ) is the second largest island in the Hawaiian archipelago, at 727.2 square miles (1,883 km2). It is the List of islands of the United States by area, 17th-largest in the United States. Maui is one of ...

. Both Molokai and Maui are parts of what used to be the much larger prehistoric island of

Maui Nui Maui Nui is a modern Geology, geologists' name given to a prehistoric Hawaii, Hawaiian island and the corresponding modern Biogeography, biogeographic region. Maui Nui is composed of four modern islands: Maui, Molokai, Molokaʻi, Lanai, Lānaʻi, ...

, to which the species appears to have been endemic. The bird evidently shared the island with another moa-nalo—the smaller

small-billed moa-nalo The small-billed moa-nalo (''Ptaiochen pau''), also known as the stumbling moa-nalo, is a species of moa-nalo, one of a group of extinct, flightless, large goose-like ducks, which evolved in the Hawaiian Islands of the North Pacific Ocean. It was ...

—which, from the sites from which its remains have been recovered, appears to have been largely restricted to upland areas over 1100 m in altitude, while the large-billed species occupied the lowlands. It was larger than its only congener, the

O'ahu moa-nalo Oahu (, , sometimes written Oahu) is the third-largest and most populated island of the Hawaiian Islands and of the U.S. state of Hawaii. The state capital, Honolulu, is on Oahu's southeast coast. The island of Oahu and the uninhabited Northwe ...

References

Anatinae Late Quaternary prehistoric birds Holocene extinctions Extinct birds of Hawaii Extinct flightless birds Biota of Maui Maui County, Hawaii Biota of Molokai

Maui Nui large-billed moa-nalo The Maui Nui large-billed moa-nalo (''Thambetochen chauliodous''), also known as the Maui Nui moa-nalo, is one of two species of moa-nalo in the genus ''Thambetochen''. Moa-nalo are a group of extinct, flightless, large goose-like ducks, which ev ...

Birds described in 1976 {{Anseriformes-stub