Evrim Yazgin
Cosmos science journalist
New analysis of New Zealand fossils first uncovered in 1987 shows how penguin wings evolved.
The wing fragments were found near the town of Duntroon on New Zealand’s South Island, nearly 1,000km southwest of the Auckland.
The fossils come from a species called Pakudyptes hakataramea. It lived during the late Oligocene (34–23 million years ago). P. hakataramea is described for the first time in a study published in the Journal of the Royal Society of New Zealand today.
Worldwide, the latter part of the Oligocene was characterised by a drying of the climate. Forests which dominated the continents, including Australia, were beginning to recede. Grasslands and prairies expanded, seeing the evolution of grazing animals.
New Zealand today is believed to be the lost, ancient continent of Zealandia breaking through to the surface. Tens of millions of years ago, Zealandia’s rocky shores and surrounding waters were a hotbed of evolutionary development.
Among the ancient marine and coastal life found in New Zealand are dolphins, seals, crabs and ancestors of tropicbirds.
New Zealand has also thrown up ancient penguin fossils. This includes the largest ever penguin which lived 55 million years ago, stood as tall as a person and weighed a whopping 150kg.
In fact, New Zealand seems to have been teeming with giant penguins.
“Most recent penguin species are small, but back in Oligocene times, giant penguins more than 1m tall were the norm,” Dr Carolina Loch tells Cosmos in an email. Loch is co-author of the new study and a researcher at the University of Otago in New Zealand.
This tremendous wealth of big-bodied penguins is what sets P. hakataramea apart.
“This seem to be the earliest of the small penguins, of a similar size of the little blue penguin,” Loch adds.
P. hakataramea would have been little more than 30cm tall. For this reason, the researchers refer to this penguin as “tiny” compared to others. Little blue penguins, found today around New Zealand and southern Australia, are the smallest penguins.
The 3 small penguin bones were housed in the collections of the Geology Museum of the University of Otago.
“After being extracted from the rock and prepared carefully, they were analysed for their overall shape (we call this morphology) to look for marks where muscles and ligaments attached,” Loch explains. “They were also analysed via cone-beam CT scanner and micro-CT scanner to study the internal details of the bone structure.”
They found a well-developed forearm bone was connected to a more archaic kind elbow joint. This, the authors write, “provides clues to the evolution of penguin wings.”
From the Late Oligocene, the researchers say that penguin wings evolved rapidly improving in both hydrodynamics and function to enable penguins to become the accomplished swimmers they are today.
“The appearance of the smallest body size and the evolution of modern wings may have led to the ecological diversity of modern penguins, which confirms the importance of Zealandia in penguin evolution,” the authors say.
This article originally stated that the New Zealand capital is Auckland. This is not correct and the article has since been updated.
