Giant Fossil Penguin From New Zealand Reconstructed
Scientists on Tuesday published in the Journal of Vertebrate Paleontology their work on a completely reconstructed fossil of a giant penguin that lived in New Zealand some 25 million years ago, work that will give researchers insight into prehistoric penguin diversity.
The fossil of the Kairuku — Maori for “diver that returns with food” — penguin, a bird that stood 4 feet 2 inches tall, was discovered embedded in a cliff at Waimate in the South Island in 1977 by Dr. Ewan Fordyce, a paleontologist from the University of Otago, New Zealand. More than 30 years later Dr. Dan Ksepka, North Carolina State University research assistant professor of marine, earth and atmospheric sciences, and North Carolina Museum of Natural Sciences colleague Dr. Paul Brinkman traveled to New Zealand to assist with reconstruction of the ancient penguin fossil.
The researchers used bones from two separate examples of the prehistoric bird and the skeleton of a modern king penguin as a guide. They quickly determined that this ancient species was much larger than the largest modern species, the Emperor penguin, which grows up to 40 inches. They found that the Kairuku weighed up to 132 pounds, twice as much as the Emperor.
The reconstruction also showed that the Kairuku penguin was easily the largest of five species of penguin that were common to New Zealand during the Oligocene epoch which lasted from 34 to 23 million years ago. The Kairuku lived from 27 to 24 million years ago.
Reconstruction efforts were inspired by the bird´s unusual body shape, unlike any other known penguin, living or extinct.
“Kairuku was an elegant bird by penguin standards, with a slender body and long flippers, but short, thick legs and feet,” said Ksepka. “If we had done a reconstruction by extrapolating from the length of its flippers, it would have stood over 6ft tall. In reality, Kairuku was around 4ft 2in tall or so.”
Fordyce said the bird´s large size was an adaptation that allowed it to swim further and dive deeper than its modern relatives. He wasn´t sure why it became extinct, but suggested climate change may have played a role or possibly increased predation from dolphins and seals.
During Kairuku´s reign, New Zealand was an attractive location for it and other penguins in terms of both food and safety, according to Ksepka. “Most of the country was underwater at that time, leaving isolated, rocky land masses that kept penguins safe from potential predators and providing them with plentiful food supply,” he told BBC News.
Researchers have long been finding exceptional fossils in New Zealand that have given significant insights into the history of the country´s marine creatures. Ksepka hopes that the reconstruction of Kairuku will give paleontologist more information about some other fossils found in the area as well as add to the knowledge about giant penguins.
“This species gives us a more complete picture of these giant penguins generally, and may help us to determine how great their range was during the Oligocene period,” Ksepka noted.
The research was funded by a grant from the National Science Foundation and support from the University of Otago.
While the Kairuku discovery and reconstruction project was a significant one for New Zealand, there have been other bigger penguin fossil discoveries in the world; at least two extinct species discovered in Peru have been found to be as much as 5 feet tall.
On the Net: