Scientists have discovered a new species of giant penguin that lived in waters around Waikato about 27 to 28 million years ago

Photo: RNZ / Olivia Allison

Fossils were found in the 1970s, but scientists could not say for sure if it was a new species of penguin, so they stayed in storage at Auckland University.

That is, until the invention of 3D printing.

This has allowed Massey University's Dr Daniel Thomas to scan the bones to American paleontologist Dr Daniel Ksepka. Both were then able to determine that they are "almost certain" it was a new type of giant penguin.

The penguin was dated by taking a fragment of the rock the bones were encased in and looking at fossil plankton. Records of fossil plankton are vast, so Dr Thomas said it was easier to determine the date.

Dr Thomas said penguin fossils become accessible as parts of the North Island that were once under water rose up over time. He could tell it was a giant penguin by comparing the thigh bone of the fossil to other penguins.

Emperor penguins are about 1 metre tall and have a thigh bone half the size of the fossil bone. Dr Thomas said it had been compared with another fossil giant penguin also, allowing them to guess that it was about 1.3 metres tall.

Dr Thomas said it did not appear to have any links to emperor penguins, other than the fact they were both penguins.

"Because it lived so far back in time, it's not a close link - they'd be very distant relatives. Definitely not a cousin or step-cousin."

As researchers only have one leg bone and other fragments, they could not tell what body shape the penguin had or its weight. But they could guess with near certainty that it was black and white, just like penguins today.

Dr Thomas said it was likely the penguin would have been a deep diver, travelling offshore to find fish.

He said the discovery was very big, as it was the first North Island fossil giant penguin to be discovered.

"Africa has fossil humans, America has fossil dinosaurs, we have a few dinosaurs, but I like to think of New Zealand as a place with giant penguins. It feeds into the idea that New Zealand is really special."