Acanthisittidae

Acanthisittidae, the New Zealand wrens, is a family of tiny passerine birds endemic to New Zealand, today reduced to two living species in two genera. Historically the family held around seven species across four or five genera during the Holocene, and five further species are known only from subfossil remains; several of the extinct species were flightless or nearly so, making the family one of the very few passerine groups to have lost the power of flight. Living New Zealand wrens are tiny, 7 to 10 centimeters long, dull green and brown, mostly insectivorous forest birds restricted to the country's main islands. Genetic studies place the family in its own ancient suborder, Acanthisitti, with no close living relatives, a lineage that may trace back to New Zealand's isolation when it broke away from Gondwana around 82 to 85 million years ago.