Australasian Science: Australia's authority on science since 1938

Ancient Penguin Reconstructed

By Stephen Luntz

The skeleton of an intimidating ancient penguin has been reconstructed, standing 30 cm taller than any modern relative and sporting a spear-like bill.

The first Kairuku, as the genus has been dubbed, was found in 1977 by PhD student Ewan Fordyce, who was seeking fossilised whales near South Canterbury in New Zealand. Fordyce, who is now a professor of palaeontology at the University of Otago, has been slowly putting together the pieces ever since, with four individuals now known. Related species have been found since the 1840s, but it is only now that a sufficiently complete skeleton has been assembled that we can work out what any of these looked like.

“We don’t know the specifics of their diet,” Fordyce says, “but they probably ate squid and fish, probably not krill. Their size would have been an adaptation that would allow them to swim further offshore and dive deeper.”

At 1.3 metres tall and weighing at least 60 kg, these ancient penguins would have needed a lot of fish to sustain them, but Fordyce says: “When the penguins lived about 27 million years ago, New Zealand seas probably offered a rich supply of food, with good nesting sites nearby”.

The reconstruction was difficult because it included bones from at least two species of the Kairuku genus.

“Kairuku was an elegant bird by penguin standards, with a slender body and long flippers, but short, thick legs and feet,” says Dr Dan Ksepka of North Carolina State University, who helped to assemble the bones. “If we had done a reconstruction by extrapolating from the length of its flippers, it would have stood over 6 feet (1.83 metres) tall.”

Fortunately two examples have been found buried in what would have initially been quiet conditions.

The name Kairuku is Maori for “diver who returns with food”. The reason for its extinction is unknown.

The work was published in the Journal of Vertebrate Paleonotology.