NZ's prehistoric penguin reconstructed

A giant penguin called a kairuku is seen in this graphic illustration. AP Photo/University of Otago)

A prehistoric penguin which stood taller than emperor penguins and had a spear-like bill has been reconstructed with the help of ancient fossils found in a hillside in the South Island.

Researchers at the University of Otago believe the kairuku ("diver who returns with food'') grew to 1.27m tall and lived in New Zealand waters 25 million years ago.

If alive today it would not be physically daunting to an adult human, but would be larger than the average Antarctic emperor penguin.

Project leader Ewan Fordyce, from Otago University, said the kairuku's larger body was an adaptation for swimming greater distances and deeper into the sea compared to modern-day penguins.

It was also more slender than emperor penguins, and had a spear-like bill and long flippers.

Professor Fordyce worked with an international team to dust off and reconstruct fossilised bones, some of which were extracted from a cliff-face in Waimate, South Canterbury 35 years ago.

Two main kairuku fossils were used, one of which Professor Fordyce found "by chance'' while searching for whale bone fossils as a post-graduate palaeontology student.

Using a king penguin as a model, the scientists reconstructed the kairuku's size and proportions.

The lead author for a paper on the bird, Dan Ksepka from North Carolina State University, said it was "an elegant bird by penguin standards, with a slender body and long flippers, but short, thick legs and feet''.

"If we had done a reconstruction by extrapolating from the length of its flippers, it would have stood over six feet tall.

"In reality, kairuku was about 4ft 2in tall [1.27m] or so.''

Researchers said most of New Zealand would have been under water at the time the bird existed, and the kairuku would have sheltered from predators on rocky outcrops.

It was believed to have been made extinct 24 to 25 million years ago, possibly because of increased predation or a change in climate.

Bigger penguins have been discovered: at least two extinct species found in Peru stood about 1.5m tall.

- Isaac Davison of the NZ Herald