Big Bird: Fossils of World's Tallest Penguin Discovered

Two ancient penguins onshore.
An artist's rendering of two Kairuku penguins onshore, passing a stranded Waipatia dolphin. (Image credit: Artwork by Chris Gaskin, owner and copyright owner: Geology Museum, University of Otago.)

New Zealand was once home to the tallest penguin species ever known — a lanky bird that stood as high as 4.2 feet (1.3 meters).

The penguin, dubbed Kairuku grebneffi, lived about 27 million years ago in a penguin paradise. More of New Zealand was underwater at the time, with only today's mountaintops emerging from the sea. That made for excellent coastal nesting for a number of penguin species.

The new fossil specimens were found beginning in the 1970s, and researchers have continued to turn up bones from the animals as recently as two months ago, said study researcher and North Carolina State University paleontologist Daniel Ksepka. The find expands the known diversity of ancient New Zealand penguins, Ksepka told LiveScience. [Images: Pudgy Penguins]

"In the past we would have thought there were one or two species living in the area," he said. "Now we know there were five."

Ksepka and his colleagues described Kairuku grebneffi and a second species, Kairuku waitaki, today (Feb. 27) in the Journal of Vertebrate Paleontology. K. grebneffi had unusually long flippers and a slim build, though its legs and feet were as short and stumpy as those of penguins today.

Researcher Daniel Ksepka with a Kairuku specimen and the bones of a modern-day Little Blue penguin. (Image credit: R. Ewan Fordyce.)

Today, penguins tend to cluster in species-specific habitats, with little overlap. Humboldt penguins dominate coastal Peru, for example, while Magellanic penguins are the main species found in Argentina. But researchers are finding that a variety of species lived side-by-side in ancient New Zealand.

Ksepka and his colleagues are using these ancient penguins to study everything from brain evolution to how the animals regulate their temperatures in frigid waters.

"Penguins are so interesting," Ksepka said. "They're so different than other birds that there's a lot we can do in the fossil record to try to understand how they became what they are."

You can follow LiveScience senior writer Stephanie Pappas on Twitter @sipappas. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.

Stephanie Pappas
Live Science Contributor

Stephanie Pappas is a contributing writer for Live Science, covering topics ranging from geoscience to archaeology to the human brain and behavior. She was previously a senior writer for Live Science but is now a freelancer based in Denver, Colorado, and regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz.