An extinct species of 1.65m tall penguins has been given the Māori name, Kumimanu, meaning ‘monster bird’.

The fossilised remains of a giant penguin as tall as a human were found in a boulder in Otago.

Scientists say the penguin was probably 1.65m tall and likely to have weighed around 100 kilograms.

Te Papa curator Alan Tennyson said the boulder containing the bones was found on an Otago beach in 2004.

“The beach was a known site for bird fossils, but only very fragmentary pieces,” he said.

“This particular rock showed some bone on the outside surface so I picked it up and brought it back to work.”

But there were no specialised staff to extract the fossilised remains and it “sat on a shelf” until 2015 when preparator Al Mannering began work.

“Painstaking extraction work slowly revealed that the rock contained a multitude of jumbled bones of a colossal penguin. We found flipper, body and leg bones and they are truly huge.”

The partial skeleton dates back to the late Paleocene of New Zealand.

Mr Tennyson said the discovery was of huge global significance.

“A massive penguin is impressive but the fact that it’s so old is important because it’s in rocks that are 55-60 million years old.

“This fossil shows massive penguins were there right from the start when penguins first evolved – and that wasn’t really known before now.”

The period was just after the demise of the dinosaurs and “right at the dawn of penguin evolution”.

“There’s probably a relationship here, so the large animals like dinosaurs, non-avian dinosaurs and marine predators, all died out at that astroid impact about 66 millions years ago.

“That probably opened up empty niches which allowed other things to grow large and fill them like this penguin.”

Mr Tennyson said giant penguins were thought to be the norm during much of the history of the birds, between 60 million and 20 million years ago until marine mammals evolved.

“At the time of the giant penguin there were no whales or seals, but by the time 20 million years came around whales and seals were really diversifying, so we think maybe they ate the giant penguins or out-competed them.”

The penguin species was given the Māori name, Kumimanu, meaning “monster bird”.

Mr Tennyson said the discovery was a career highlight.

“This is definitely one of the most exciting fossils that I’ve ever found.

“When we found it we didn’t know what it was, because it was completely encased in rock. But as soon as the extraction began, we realised that is was the remains of an enormous bird.”