Julia Clarke: Penguin ancestors didn’t wear black and white
Penguins didn’t always have black and white feathers, according to Julia Clarke,a paleontologist at the University of Texas – Austin. In October 2010, her research team reported the discovery of the first fossilized penguin with evidence of feathers. The new species lived 36 million years ago in Peru. And it turns out that the feathers of these ancient penguins were not black and white, Clarke told EarthSky.
It’s kind of striking, because it plays with your notion of what a penguin is. It would have been gray and a reddish brown color, very unlike our tuxedoed living penguins.
Scientists determined the color of the ancient bird feathers by analyzing the microscopic structures that would have held the feather’s original pigment – the same type of pigment that gives color to human hair. Clarke said the fossil reveals that penguins didn’t develop their trademark black and white color scheme until later in their history.
There’s this first insight into penguin feathering – penguin feather color, and penguin feather shape, and it really brings to life part of the early interval in penguin evolution.
Dr. Clarke also described the newly-discovered species as a ‘giant penguin’ – twice as big as today’s largest penguins.
It would have been much larger the penguins we have today. And the beaks on these giant penguins are enormous.
Clarke said scientists aren’t yet sure of why penguins changed colors, but they know that penguin feathers are unlike any other bird feathers on Earth. She said:
The new findings really prompt us to ask questions we never knew to ask. We didn’t know until we started looking at the fossil that living penguins are so weird; they have these aberrant structures that weren’t seen in any other birds alive today. I think that shows us something remarkable about looking to the past and paleontology.
She’s talking about the way that penguin feathers produce color, which is contained in these microscopic structures called melanosomes. When her team added penguins to the library of living bird colors, they discovered something new. She explained:
What we found is that living penguins make that brown-black color in a way that is not known in any other birds or non-avian dinosaurs. They have these relatively giant melanosomes that are very broad.
But ancient penguins’ melanosomes have similar size, shape and dimensions to living birds. So that means at some point, Clarke said, penguin feathers underwent a drastic change. She said that the new fossil shows that penguin colors have changed radically over the last 50 million years.
She added that the fact that the penguin fossil was found in Peru, during a warm period in Earth’s climate, changes scientists’ ideas about the early evolution of penguins. Previously, scientists believed that ancient penguins lived in low latitudes, like Antarctica, and reached higher latitudes, like the Galapagos Islands, fairly recently.