Thambetochen is an extinct genus 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 ...

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 ...

. It contains two species, the

Maui Nui 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 ...

(''T. chauliodous'') and the smaller

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 ...

(''T. xanion''). Thambetochen xanion

The former was found on

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 ...

and

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 ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

, the latter was found on

Oahu 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 ...

. These birds were large, flightless ducks, with robust legs but small wings, which had evolved in isolation, on islands without terrestrial mammals. Their beaks had tooth-like

lamella Lamella (: lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal * Lame ...

e and their diet was plants which they digested through

hindgut fermentation Hindgut fermentation is a digestive process seen in monogastric herbivores (animals with a simple, single-chambered stomach). Cellulose is digested with the aid of symbiotic microbes including bacteria, archaea, and eukaryotes. The microbial fe ...

. These birds were likely driven to extinction when the islands were colonised by

Polynesians Polynesians are an ethnolinguistic group comprising closely related ethnic groups native to Polynesia, which encompasses the islands within the Polynesian Triangle in the Pacific Ocean. They trace their early prehistoric origins to Island Sout ...

References

{{Taxonbar, from=Q7709821 Anatidae Holocene extinctions Extinct flightless birds Extinct birds of Hawaii Late Quaternary prehistoric birds Endemic fauna of Hawaii Bird genera Fossil taxa described in 1976