This story about DNA from the extinct New Zealand Haast's eagle is old news, but cool nonetheless. I ran across it doing some reading about the mammoth DNA.
[UK's National Environment Research Council] says: "Haast's eagle is the only eagle known to have been the top predator in a major terrestrial ecosystem.
"They hunted moa, the herbivorous, flightless birds of New Zealand [now also extinct], which weighed up to 200kg (31st 7lb).
"With a truncated wingspan of around three metres, for flying under the forest canopy, the eagles struck their prey from the side, tearing into the pelvic flesh and gripping the bone with claws the size of a tiger's paw.
"Once caught, the moa would be killed by a single strike to the head or neck from the eagle's other claw."
The neat thing is the DNA phylogeny. The study showed that the 10 - 14 kg Haast's eagle was most closely related to the 1 kg "little" eagle of Australia and New Zealand, and that they share a common ancestor within the last million years.
"It means that an eagle arrived in New Zealand and increased in weight by 10 to 15 times over this period, which is very fast in evolutionary terms. Such rapid size change is unprecedented in birds and animals."
The bird was a sort of island giant, in other words -- clearly because of the predatory niche available in the lack of mammal predators.