By | October 12, 2016 01:20pm ET
More than 66 million years ago, a duck-size waterbird flew around the woods of ancient Antarctica, honking and calling to its mate with what is now the oldest discovered avian vocal organ on record, a new study finds.
The findings also suggest that dinosaurs, for which no vocal organ has been found, likely didn't sing and tweet like birds do.
The vocal organ, known as a syrinx, is tiny: about the width of a pencil and less than 0.3 inches (1 centimeter) tall. But it's an enormous finding for experts piecing together the evolutionary history of birds, said lead study researcher Julia Clarke, a professor of vertebrate paleontology at the University of Texas at Austin.
"This is the avian vocal organ, which is unique amongst all vertebrates," Clarke told Live Science. "There's virtually nothing written about its origin or early evolution."
The newly discovered syrinx belonged to Vegavis iaai, a Cretaceous-age bird found on Antarctica's Vega Island. Researchers from the Argentine Antarctic Institute found specimens of the bird in 1992 and sent the fossils to Clarke to examine. In previous work, detailed in a 2005 study in the journal Nature, Clarke and her colleagues found that the bird is related to modern ducks and geese.
In 2013, Clarke was looking at the micro-computed tomography (micro-CT) scans of one of the 1992 Vegavis iaai specimens when a tiny detail caught her attention. It was the syrinx.
"I had actually started thinking about the fossilization potential of the syrinx," Clarke said. "I was shocked to find that this fossil, which had actually been in my lab for a number of years, had a fossil syrinx."