Up To Four Species Of Penguin Once Lived In Africa, New Fossil Study Finds

Newly discovered penguin fossils found in southern Africa predate continent's oldest penguin fossils by five to seven million years, shedding light on the evolutionary history of the flightless birds and confirming that as many as four species of penguin once lived on the continent.

In 2010 Daniel Thoman and Dan Ksepka were sifting through rock and sediment excavated from an industrial steel plant near Cape Town, South Africa when they happened upon a jumble of shark teeth, fossils and what they recognized as pieces of backbones, breastbones, wings and legs of several extinct species of penguin.

After examining the bone fragments, they deduced that the specimens were as small as a foot tall, to birds closer to three feet tall, encompassing the full size spectrum of the birds.

Only one species of penguin lives in Africa today, the black-footed penguin, Spheniscus demersus, also known as the jackass penguin for its distinct, donkey-like bray.

Scientists are unsure exactly when penguin diversity in Africa plummeted, because a gap in the fossil record makes it difficult to determine whether the extinction happened suddenly or gradually.

In a press statement, Ksepka likens the fossil records to a broken reel of film that only shows some of the picture.

"We have a frame at five million years ago, and a frame at 10-12 million years ago, but there's missing footage in between," said Ksepka, who co-authored a paper on the fossil findings with Thomas.

Humans are not likely to blame for the extinction of Africa's penguins, the researchers say, because by the time early modern humans arrived in South Africa all but one of the continent's penguin species had already died out.

They posit a more likely scenario of rising and falling sea levels ending the penguins by destroying safe nesting sites. Some five million years ago, when at least four species of penguin lived on what we call Africa, the sea level on the South African coast was as much as 300 feet higher than it is today. As sea levels fell, the safety of the nesting sites was likely compromised as more predators were afforded access to the offshore islands where the penguins nested.

Daniel Thomas of the National Museum of Natural History and Dan Ksepka of the National Evolutionary Synthesis Center, published their paper on the fossil findings in the March 26 issue of Zoological Journal of the Linnean Society.