It was previously thought that the ancestors of today’s flightless birds (the ostrich, emu, etc.) were also flightless. However, a new study shows that they only began exploring the ground in earnest after dinosaurs became extinct.
Using fossil DNA, Phillips and colleagues analyzed the genome of a giant moa, an extinct flightless bird that lived in what is now New Zealand.
The team found that the moa’s closest relatives were tinamous—small ground-dwelling birds still found in South America that can barely fly.
During most of the Cretaceous period (146 to 65 million years ago), South America, New Zealand, Australia, and Antarctica were joined as part of the massive southern continent Gondwana. About 80 million years ago, New Zealand drifted away from Gondwana.
The researchers suggest that a moa ancestor may have flown from another location—possibly what would become South America—to New Zealand, where the bird hopped to the ground and eventually evolved into the moa.