Ornimegalonyx

Ornimegalonyx (also known as the Cuban Giant Owl or Cuban Cursorial Owl) is a genus of giant owl from Pleistocene Cuba. It is the largest owl to have ever existed.

Description
The height of Ornimegalonyx is estimated to have been about 1.1 meters, and its weight over 9 kilograms. Its legs and feet were very large and well-built, and likely adapted for running.

History
Ornimegalonyx was originally described in 1954 by Oscar Arredondo, who identified it as a type of terror bird due to its size. In 1961, Pierce Brodkorb found the fossils to be those of a giant owl. Remains of Ornimegalonyx are common in Cuba, and four species in total have been described.

Diet
Ornimegalonyx was a predator, and probably hunted large rodents and ground sloths. Comparisons with modern owls indicate that it could likely kill animals that were much larger than itself.