The new discovery, detailed in the March 26 issue of the Zoological Journal of the Linnean Society, could shed light on why the number of penguin species plummeted on Africa's coastline from four species 5 million years ago to just one today — Spheniscus demersus, or the jackass penguin, known for their donkeylike calls.
Daniel Thomas, a researcher at the National Museum of Natural History, and colleague Daniel Ksepka of the National Evolutionary Synthesis Center were studying rock sediments near a steel plant in Cape Town, South Africa, when they uncovered an assortment of fossils, including 17 pieces that turned out to be backbones, breastbones, legs and wings from ancient penguins.
The bones suggested these ancient birds ranged from 1-to-3 feet tall (0.3 to 0.9 meters). For comparison, Africa's living jackass penguin, also called the black-footed penguin, stands at about 2-feet tall (0.6 meters) and weighs between 5.5 and 8.8 pounds (2.5 and 4 kilograms).
The discovery pushes back the penguin fossil record in Africa by at least 5 million years.
Because the next oldest fossils from Africa date to 5 million years ago, it's tricky to determine exactly why most penguin species disappeared from Africa.
"It's like seeing two frames of a movie," Ksepka said in a statement. "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."
One possibility is that changing sea levels eliminated most of the penguins' nesting sites.
About 5 million years ago, sea levels were 296 feet (90 m) higher than today, and the low-lying South Africa became a patchwork of islands. Those islands provided beaches for several penguin species to create nests and rear their young while sheltering them from predators.
Read more at Discovery News
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