If you’ve never heard of the adzebill…
I’m with you. I never heard of it before either. The adzebill (genus: Aptornis, sometimes Apterornis; early Miocene to Holocene; Owen 1844; Figs. 1,2) is a recently extinct large (80 cm in length) flightless bird found only in New Zealand. The question is, what is it?
A little backstory.
An adze is a tool similar to an ax with an arched blade at right angles to the handle, used for cutting or shaping large pieces of wood. This bird, like the extant kagu, uses its beak as an adze, but the beak and the extant bird are not as derived as in the extinct bird.
Aptornis has “been placed in the Gruiformes (cranes) but this is not entirely certain.” The report also includes possible relationships to the kagu (Rhynochetos), trumpeters (Psophia), moas (Dinornis, Figs. 3, 4), and the sunbittern (Eurypyga). None of these birds are related to each other in the LRT.
Musser 2017 reports:
“Past morphological studies placed Aptornis as a sister taxon to Rhynochetos jubatus, but recent genomic studies reveal R. jubatus and Eurypyga helias to be sister taxa, and posit that Aptornis falls within Gruoidea.” Musser’s study found strong support for a sister relationship between the kagu, Rhynochetos, and the sunbittern, Eurypgya, but Aptornis nested with the trumpeter, Psophia.
(Owen 1844; 80 cm in length) is the extinct flightless adzebill, which nests with the extinct moa, Dinornis. The rostrum is sharp, short and turns down. The hind limbs are robust. The wings are vestiges.
is the closest island to New Zealand. These islands which were once contiguous when ocean levels were lower.
Musser GM 2017. Resolving the radiation and phenotypic evolution of basal neoaves: beginning construction of a new morphological dataset and a novel sister taxon for Aptornis. Journal of Vertebrate Paleontology abstracts 2017: 167.
Owen R 1844. On Dinornis, an extinct genus of tridactyle struthious birds, with descriptions of portions of the skeleton of five species which formerly existed in New Zealand. (Part I.) Transactions of the Zoological Society of London, 3(3): 235–275,