'One of world's oldest bird species discovered'

Scientists have discovered fossils of one of the world's oldest bird species in New Zealand that lived about 62 million years ago, soon after the dinosaurs died.

Bony-toothed birds (Pelagornithids), an ancient family of huge seafaring birds, were thought to have evolved in the Northern Hemisphere -- but that theory has been upended by the discovery of the family's oldest, but smallest member in North Canterbury, New Zealand.

At 62 million-years-old, the newly-discovered Protodontopteryx ruthae, is one of the oldest named bird species in the world, according to the study published in the journal Papers in Palaeontology.

While its descendants were some of the biggest flying birds ever, with wingspans of more than five metres, Protodontopteryx ruthae was only the size of an average gull, researchers said.

Like other members of its family, the seabird had bony, tooth-like projections on the edge of its beak, they said.

The seabird fossil was identified by the same team that recently announced the discovery of a 1.6 metre-high giant penguin from the same site.

Amateur paleontologist Leigh Love found the partial Protodontopteryx skeleton last year at the Waipara Greensand fossil site.

The bird was named Protodontopteryx ruthae after Love's wife Ruth, researchers said.

According to Paul Scofield, a curator at Canterbury Museum in New Zealand, the age of the fossilised bones suggests pelagornithids evolved in the Southern Hemisphere.

"While this bird was relatively small, the impact of its discovery is hugely significant in our understanding of this family," Scofield said.

"Until we found this skeleton, all the really old pelagornithids had been found in the Northern Hemisphere, so everyone thought they'd evolved up there," he said.

Gerald Mayr of Senckenberg Research Institute and Natural History Museum in Germany said the discovery of Protodontopteryx was "truly amazing and unexpected."