Eyles' Harrier was a giant endemic harrier of NZ which became extinct after the arrival of Maori and before the arrival of Europeans. NZBirdsOnline describes it as being "the size of a small golden eagle", and an estimated four times heavier than the extant Australasian Swamp Harrier Circus approximans which is found in NZ today - the small skull in the photo is that of C. approximans.