South Island giant moa in the context of "Elephant bird"

Moa (order Dinornithiformes) are an extinct group of flightless birds formerly endemic to New Zealand. During the Late Pleistocene-Holocene, there were nine species (in six genera). The two largest species, Dinornis robustus and Dinornis novaezelandiae, reached about 3.6 metres (12 ft) in height with neck outstretched, and weighed about 230 kilograms (510 lb) while the smallest, the bush moa (Anomalopteryx didiformis), was around the size of a turkey. Estimates of the moa population when Polynesians settled New Zealand circa 1300 vary between 58,000 and approximately 2.5 million.

Moa are traditionally placed in the ratite group. Genetic studies have found that their closest relatives are the flighted South American tinamous, once considered a sister group to ratites. The nine species of moa were the only wingless birds, lacking even the vestigial wings that all other ratites have. They were the largest terrestrial animals and dominant herbivores in New Zealand's forest, shrubland, and subalpine ecosystems until the arrival of the Māori, and were hunted only by Haast's eagle. Moa extinction occurred within 100 years of human settlement of New Zealand, primarily due to overhunting.

Dinornis (from Ancient Greek δεινός (deinós), meaning "terrible", and ὄρνις (órnis), meaning "bird"), also known as the giant moa, is an extinct genus of birds belonging to the moa family. As with other moa, it is a member of the order Dinornithiformes. It was endemic to New Zealand. Two species of Dinornis are considered valid, the North Island giant moa (Dinornis novaezealandiae) and the South Island giant moa (Dinornis robustus). In addition, two further species (new lineage A and lineage B) have been suggested based on distinct DNA lineages.

Moa (order Dinornithiformes) are an extinct group of flightless birds formerly endemic to New Zealand. During the Late Pleistocene-Holocene, there were nine species, in six genera. The two largest species, Dinornis robustus and Dinornis novaezelandiae, reached about 3.6 metres (12 ft) in height with neck outstretched, and weighed about 230 kilograms (510 lb); the smallest, the bush moa (Anomalopteryx didiformis), was about the size of a turkey. Estimates of the moa population when Polynesians settled New Zealand circa 1300 range from 58,000 to 2.5 million.

Moa are traditionally placed in the ratite group. Genetic studies have found that their closest relatives are the flighted South American tinamous, once considered a sister group to ratites. The nine species of moa were the only wingless birds, lacking even vestigial wings, which all other ratites have. They were the largest terrestrial animals and dominant herbivores in New Zealand's forest, shrubland, and subalpine ecosystems until the arrival of the Māori, and were hunted only by Haast's eagle. Moa extinction occurred within 100 years of human settlement of New Zealand, primarily because of overhunting.

Late Quaternary prehistoric birds are avian taxa that became extinct during the Late Quaternary – the Late Pleistocene or Early Holocene – and before recorded history, specifically before they could be studied alive by ornithological science. They had died out before the period of global scientific exploration that started in the late 15th century. In other words, this list deals with avian extinctions between 40,000 BC and AD 1500. For the purposes of this article, a "bird" is any member of the clade Neornithes, that is, any descendant of the most recent common ancestor of all currently living birds.

The birds are known from their remains, which are subfossil; as the remains are not completely fossilized, they may yield organic material for molecular analyses to provide additional clues for resolving their taxonomic affiliations. Some birds are also known from folk memory, as in the case of Haast's eagle in New Zealand.