The Aptornithidae is an extinct bird family only known from New Zealand.  They have traditionally been associated with the rails, in spite of their large size, roughly that of Great Bustard, Otis tarda. 

Affinities with the Kagus have also been postulated. In 1995, Weber & Hesse expressed their suspections that the Galloanserae may be the sister group to the Aptornithidae, on the basis of cranial characteristics.

I know of no reasonably acceptable vernacular name for this family in English.

Aptornis otidiformis
Owen   1844
Holocene of North Island, New Zealand
Primary materials: Nearly complete skeleton

Erich Weber & Angelika Hesse,
The systematic position of Aptornis, a flightless bird from New Zealand
Courier Forschungsinstitut Senckenberg 181 (1995): 292-301

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Aptornis defossor
Owen   1844
Holocene of South Island, New Zealand
Primary materials: Complete skeleton
Larger than A. otidiformes

Erich Weber & Angelika Hesse,
The systematic position of Aptornis, a flightless bird from New Zealand
Courier Forschungsinstitut Senckenberg 181 (1995): 292-301

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