Penguins are much older than previously thought and their evolution probably dates back to the days of the dinosaurs, according to research on fossilised remains in Canterbury Museum.
The leg bone and toes from a giant ancient penguin were found by an amateur collector in rocks near Waipara.
A study by Dr Gerald Mayr, of the Senckenberg Research Institute in Germany, and Canterbury Museum scientists Professor Paul Scofield and Dr Vanesa De Pietri has been published in the The Science of Nature.
The researchers estimate the penguin was about 1.50m tall and say the find is one of the oldest penguin fossils in the world, dating back 61 million years.
The bones differ substantially from previous penguin finds of a similar age and show that the variety of Palaeocene penguins, living between 66 and 56 million years ago, was greater than previously thought.
This diversity indicates that penguins started to evolve quite early, likely during the late Cretaceous period (the era of the dinosaurs).
Dr Mayr, the study's lead author, says penguins had reached enormous proportions early on in their evolutionary history.
He says they were already more diverse 60 million years ago than previously assumed.
This diversity indicates that penguins probably evolved during the "Age of the Dinosaurs" more than 65 million years ago.