A penguin about the size of a human has been unearthed in Waipara, North Canterbury.

Photo: Canterbury Museum CC BY NC / Supplied

The fossilised bones of Crossvallia waiparensis were found by amateur palaeontologist Leigh Love at the Waipara Greensand fossil site in North Canterbury last year.

Five other penguin species have been discovered at the same site.

The species was alive between 56 million and 66 million years ago, during the paleocene epoch, weighed up to 80kg and about 1.6m tall, one of the largest penguins ever discovered.

Canterbury Museum curators Dr Paul Scofield and Dr Vanesa De Pietri, and Dr Gerald Mayr of Senckenberg Natural History Museum in Frankfurt, Germany, analysed the bones, and local Al Mannering prepared them for study and helped describe them.

Dr Mayr said the discovery made the understanding of penguin evolution a lot clearer.

"There's more to come, too - more fossils which we think represent new species are still awaiting description."

Analysis of the penguin's feet suggested they used them for swimming much more than their modern relatives and possibly had not yet adapted to standing upright.

The bird's closest known relative is probably the Crossvallia unienwillia, a partial fossilised skeleton of which was found in Antarctica's Cross Valley in 2000.

When the penguins would have been alive, Antarctica had a very different climate and was probably covered in forest.

News of the find follows the discovery of the world's largest parrot in North Otago, and adds to our knowledge of other gigantic but extinct New Zealand animals including other giant penguins, a giant eagle, the giant burrowing bat, and moa.

The fossils of several giant species will be displayed in a new exhibition about prehistoric New Zealand at Canterbury Museum later this year.