This giant penguin ruled New Zealand 25 million years ago

Because of its extreme isolation from any other major landmass, New Zealand's unique native ecosystem is literally for the birds. And these rather elegant-looking penguins briefly dominated this bird paradise, back when New Zealand was mostly underwater.

This artist's conception depicts the Kairuku penguin, a Maori term that loosely means "diver who returns with food." The bones of this particular penguin species were first discovered way back in 1977, but it's only now that North Carolina State researcher Dr. Dan Ksepka and his colleague Dr. Paul Brinkman from the North Carolina Museum of Natural Sciences have been able to reconstruct what the penguin would have looked like.

Before the Maori arrived on New Zealand about 800 years ago, there were only three mammal species on all of New Zealand, all bats. In the absence of the dominant class of animal life, birds evolved to fill all the available ecological niches, creating gigantic, ostrich-like grazing birds like the moa and enormous birds of prey like Haast's eagle. And while these species dominated New Zealand at the time of the arrival of the Maori, the country wasn't always so favorable to terrestrial birds. As Dr. Ksepka explains, the New Zealand of 25 million years ago was perfect for oceangoing birds like Kairuku:

"The location was great for penguins in terms of both food and safety. Most of New Zealand was underwater at that time, leaving isolated, rocky land masses that kept the penguins safe from potential predators and provided them with a plentiful food supply."

This species was the largest of the five penguin species that lived on New Zealand at the time. At about four feet two inches tall, it would have been a couple inches taller than the Emperor Penguin, the biggest living penguin. We're not yet completely sure what was the largest penguin ever, although the current estimate seems to be at about six feet tall. In fact, if Kaikuru was built somewhat differently, it might actually have tied that record, as Dr. Ksepka observes:

"Kairuku was an elegant bird by penguin standards, with a slender body and long flippers, but short, thick legs and feet. If we had done a reconstruction by extrapolating from the length of its flippers, it would have stood over 6 feet tall. In reality, Kairuku was around 4-feet-2 inches tall or so."

The paleontologists say that they reconstructed Kaikuru from two different fossil specimens, using the living King Penguins species as a guide. For more, including the abstract of the original paper, check out the North Carolina State website.

Artwork by Chris Gaskin, owner and copyright owner: Geology Museum, University of Otago. Used with permission.