30 April 2016

Fossils may reveal 20-million-year history of penguins in Australia

AUSTRALIA - A study has found that there have been multiple times that different groups of penguins arrived and established themselves in Australia after the continent split from Antarctica. The arrivals included a group of 'giant penguins' that may have lived in Australia after they went extinct elsewhere. The study, by Travis Park from Monash University and colleagues, was recently published in the open-access journal PLOS ONE.

Penguin evolution in Australia after the continent's pre-historic split from Antarctica is not well-understood, but the fossil record shows that Australia was home to a number of penguin species. Only the little penguin remains today, and we lack evidence of this species and its ancestors in Australia before the Quaternary Period (about 2.5 million years ago). To update our understanding of Australian penguin evolutionary history, the authors of the study analysed recently collected penguin fossils and compared them to known species, including now-extinct 'giant penguins'. They then presented a new evolutionary tree in the context of biogeographical events on the Australian continent.

The authors propose that Australia's unique biogeographical history allowed for multiple dispersals of penguins to the continent during the Cenezoic Era (the Age of Mammals), and that ancestors of the modern little penguins arrived in Australia with the help of a strengthened Antarctic Circumpolar Current.

While evolutionary trees are constructed as best estimates based on sometimes limited fossil records, the authors suggest these findings shed new insights into the evolutionary trajectory of penguins in Australia.

Journal citation
Park T., Fitzgerald E.M.G., Gallagher S.J., Tomkins E., & Allan T. (2016). New Miocene Fossils and the History of Penguins in Australia. PLoS ONE 11(4): e0153915. doi:10.1371/journal.pone.0153915

Source
Fossils may reveal 20-million-year history of penguin in Australia [press release], PLOS, 26 April 2016, EurekAlert!

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