New Zealand was a penguin paradise about sixty-two million years ago with a diverse range of species that evolved giant pointy beaks to catch the plentiful fish in the waters off North Canterbury.
An international team of researchers has identified four new species of ancient penguin from fossils found in the Waipara Valley, North Canterbury. Co-author and Canterbury Museum Senior Curator Natural History, Dr Paul Scofield, says the fossils upend our understanding of ancient penguins.
“This is increasing our understanding of the paleoecology of the area. What is really astounding is the diversity of penguin species. It is greater than any other site in the world today,’’ he says.
“We had assumed there was just one medium sized penguin but when we looked more closely we discovered the diversity was remarkable.”
The researchers – from Senckenberg Research Institute, University of Canterbury, University of Arizona, Flinders University, University of Texas, Canterbury Museum and GNS Science – identified the new species from the wealth of new fossils recovered from the area in the last 20 years. The findings were recently published in the Zoological Journal of the Linnean Society.
“Up until fairly recently, because we had fragmentary material, we assumed there was just one penguin species. Now we have much better material we are confident it was a diverse population.”
Dr Scofield says the long beaks were either used like a dagger to spear fish, or like forceps to pluck them from the water. In all of the species where a beak was recovered, it was extremely long and pointed, measuring about 65% of the entire skull length.
“That’s totally different to a modern penguin, which swims through the water with an open mouth and catches whatever gets in its way,” he says.
“It’s a strange thing. There is nothing like it today. When you compare fossils to existing breeds you usually find something similar but none of today’s diving birds have similar bills.”
The recently discovered penguin species range in size from an Emperor Penguin down to the smaller Yellow Eyed Penguin. They are smaller than the 1.6 metres tall ancient penguin species identified from fossils in Waipara in 2019.
The new fossils are amongst the oldest and most complete penguin remains ever found and reinforce New Zealand’s claim to be the birthplace of penguins. The remains were possibly preserved by crabs dragging dead penguins into their burrows to eat.
Some of the penguin fossils consist of bone clusters, so researchers used medical scanners to identify different bones in the tangle of remains.
The fossils were discovered in strata dating from 62.5 to 58 million years ago. The ancient penguins didn’t have the stiff flippers seen in modern species, which evolved at a later stage.
Co-author Dr Vanesa De Pietri of Te Whare Wānanga o Waitaha | University of Canterbury says: “The evolutionary changes we see in the wings of these Paleocene penguins likely represented a major adaptive leap. So while the beak length remained surprisingly stable for more than 20 million years during early penguin evolution, the shape of their limbs was refined relatively rapidly”.
The discovery of four new species brings the number of known ancient penguin species that lived in the region to ten.
Co-author Dr Gerald Mayr of Senckenberg Research Institute says: “The succession of increasingly more modern-like penguin forms found within the Waipara Greensand fossils supports New Zealand as a critical region for penguin evolution.”