Penguin Ancestor as Big as Men

The giant penguin’s fossilized remnants were found in the Otago region on New Zealand’s South Island. “Age datings reveal that the bird lived during the Late Paleocene, i.e., about 59 to 56 million years ago,” explains Mayr, and he adds, “The fossils are therefore among the oldest known penguin remains, and it is remarkable that even these early forms reached such an enormous size.”

In the study, the ornithologist from Frankfurt and his colleagues from New Zealand further demonstrate that phylogenetically, the new discovery represents a rather archaic species, which is clearly differentiated from the giant penguins known to date from the geologically younger epochs of the Eocene and Oligocene. “Kumimanu shows that gigantism was not rare among early penguins, even at the earliest stage of their evolution,” adds Mayr.

The humerus (top) and a bone from the shoulder girdle (coracoid, bottom) of the Paleocene giant penguin Kumimanu biceae, compared to the corresponding bones of one of the largest fossil penguins known to date (Pachydyptes ponderosus from the Eocene in New Zealand) and those of an Emperor Penguin (Aptendodytes forsteri).

Credit: © Senckenberg

The scientists assume that this gigantism developed as a result of the seabirds’ flightlessness. This raises the question why no penguin giants are alive today. The researchers offer the following hypothesis: “Giant penguins developed shortly after the mass extinction near the end of the Cretaceous, approx. 66 million years ago. It is possible that the disappearance of large marine reptiles enabled the penguins to explore new ecological niches. However, with the subsequent appearance of other large marine predators such as seals and toothed whales, the penguins faced new competition and predation – which may have led to their extinction.” The Senckenberg scientist and his colleagues now hope for additional discoveries that can shed light on this and other new questions.

Contacts and sources:
Dr. Gerald Mayr
Senckenberg Forschungsinstitut und Naturmuseum Frankfurt

Judith Jördens
Senckenberg Gesellschaft für Naturforschung

Publication
Gerald Mayr, R. Paul Scofield, Vanesa L. De Pietri & Alan J.D. Tennyson (2017): A Paleocene penguin from New Zealand substantiates multiple origins of gigantism in fossil Sphenisciformes. NATURE COMMUNICATIONS 8: DOI: 10.1038/s41467-017-01959-6 |www.nature.com/naturecommunications