- Temporal range: Holocene
- Fossil location: New Zealand (subfossil remains)
- Known species: A. otidiformis, A. defossor
The two Aptornis species are commonly known as the North Island Adzebill (A. otidiformis) and the South Island Adzebill (A. defossor). Both species were endemic to New Zealand until they were driven to extinction by hunting pressure from Polynesian settlers as well as predation of eggs and hatchlings by dogs and rats who had accompanied the humans to their new home. As a result, the birds were never encountered alive by European explorers.
The North Island Adzebill was smaller than its South Island cousin, but both species were quite massive, about the size of small moa (with which they were initially confused upon discovery). The genus was omnivorous and may have fed on large invertebrates, lizards, tuataras and even small birds. The bird’s taxonomic placement is uncertain; it may belong in Gruiformes with the cranes and rails or in Eurypygiformes with the Kagu.