The Lesser Megalapteryx or Upland Moa (Megalapteryx didinus) was a flightless bird native to the northern part of New Zealand. It became extinct around the 14th century AD. Early on it was possible that they could take flight but as they evolved they grew in size, with the larger ones reaching nearly 500 pounds and standing 12 feet high.
It is belived that they were hunted and killed off as the the Polynesian ancestors of the Maori settled in the region. Although there is some speculation that a form of the bird survived until much later (possibly till the 19th century). As they had no natural predators (there were no land mammals living on New Zealand) they were quite unprotected against attacks by Maori.
Nonetheless, check out this insane preserved foot from an obviously very large one. I think this may give me nightmares tonite. At the very least it gives me the heebie-jeebies.