Three small penguin bones, collected in New Zealand's South Canterbury in 1987, have played a huge role in the evolutionary history of the bird and are now shedding new light on how penguin wings have evolved, an international study said on Thursday.
The study describes a new species of fossil penguin that lived in Otago about 24 million years ago. Named Pakudyptes hakataramea, the penguin was about the same size as the little blue penguin, the smallest in the world.
The appearance of such small penguins and the evolution of modern wings may have led to the ecological diversity of modern penguins, which confirms the importance of Zealandia in penguin evolution, said the study published in the Journal of the Royal Society of New Zealand.
Around the Late Oligocene when the tiny penguin lived, changes in penguin wings were occurring rapidly, as well as other changes that enabled modern penguins' excellent swimming abilities, according to the researchers from the University of Otago, Japan's Okayama University of Science and Osaka University, among others.
Analyzing three bones -- a humerus, femur and ulna, researchers said Pakudyptes fills a morphological gap between modern and fossil penguins, with the humerus and ulna highlighting how penguins' wings have evolved.
"Pakudyptes is the first fossil penguin ever found with this combination, and it is the 'key' fossil to unlocking the evolution of penguin wings," said lead author Tatsuro Ando.
The ability of Pakudyptes to dive and swim comes down to the distinctive combination of its bones, which may have contributed to the ecological diversity of modern penguins, the researchers said.