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.

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 lamellae and their diet was plants which they digested through hindgut fermentation.

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