Contributions to New Zealand’s Late Quaternary avifauna. II: Dendroscansor decurvirostris, a new genus and species of wren (Aves: Acanthisittidae)

Abstract

Dendroscansor decurvirostris, a new and particularly distinctive New Zealand wren (Aves: Acanthisittidae), is described from subfossil remains found in Late Pleistocene -Holocene cave sediments in the north-western South Island, New Zealand. Dendroscansor, uniquely among acanthisittids, has an extraordinarily elongate, downcurved bill. This feature, and others such as its enlarged anterior cervical vertebrae and relatively short, yet not particularly robust legs, suggest that the species was largely arboreal, probing in crevices in tree bark (and perhaps also in fallen logs) in the manner of the various creepers (e.g. Dendrocolaptidae, Furnariidae, Certhiidae, Climacteridae). In general, the post-cranial skeleton of Dendroscansor exhibits characteristics allying it more closely with Pachyplichas and Traversia than with Xenicus and the diminutive Acanthisitta. Its much reduced wing skeleton and almost acarinate sternum provide compelling evidence that, like Pachyplichas and Traversia, it was incapable of flight. © 1991 Journal of the Royal Society of New Zealand.