Long-billed Wren (New Zealand)

The Long-billed Wren (Dendroscansor decurvirostris) was a species of New Zealand wren (family Acanthisittidae) endemic to the South Island of New Zealand. It was the only species in the genus Dendroscansor. The Long-billed Wren was a tiny bird with stout legs, tiny wings and a reduced sternum, suggesting that it had weak flight muscles and was probably flightless, like the recently extinct Stephens Island Wren. Its weight is estimated at 30 g, which makes it heavier than any surviving New Zealand wren but lighter than the also extinct Stout-legged Wren. The bill of this species was both long and curved, and unlike that of the rest of the family.

The species is known only from fossils at four sites across South Island. It is the rarest fossil wren from New Zealand and presumably was the least common species when it was still extant. It is thought to have had an alpine distribution (like the surviving Rock Wren) based on the locations of the fossils.

The Long-billed Wren was extinct before the arrival of European colonists and explorers in New Zealand. It was among the first wave of native bird species to go extinct after the introduction of the Polynesian rat. Like many New Zealand species, the Long-billed Wren presumably had few defences against novel predators such as the rat.