The fossilised skeleton of a small bird may help researchers better understand the pace at which birds diversified after the dinosaurs went extinct 66 million years ago, a new research suggests.
Researchers say that this fossil – which is about 62 to 62.5 million years old – is the oldest modern bird fossil ever to be found in North America. According to the researchers, it shows that modern birds evolved much quickly than it was previously believed – only three to four million years after the dinosaur mass-extinction.
Tom Williamson, a curator of palaeontology at the New Mexico Museum of Natural History and Science, said that birds started intensely diversifying right after the Cretaceous period ended.
About 150 million years ago – during the Jurassic period – birds had already begun their evolutionary split from dinosaurs. Unfortunately, many bird lineages died out after the asteroid (6 miles/ 10 km long) impact, which took place roughly 66 million years ago.
Probably less than a dozen bird lineages managed to survive the catastrophe, Daniel Ksepka, a curator of science at the Bruce Museum in Greenwich, Connecticut, stated. Nowadays there are about 40 bird lineages that include more than 10,000 species.
The new-found fossilised bird skeleton may shed some light on how quickly bird diversity sky-rocketed, Ksepka said.
The bird skeleton was found in 2007 in New Mexico. Williamson excavated the bird’s tiny bones, which led him to believe that the bird was probably no larger than the size of a human fist.
Williamson, Thomas Stidham, an avian palaeontologist at the Institute for Vertebrate Palaeontology and Palaeoanthropology in Beijing, and Ksepka analysed the bird fossils.
The researchers found that the species is part of an extinct family of birds that is related to mouse birds and owls. The new-found species is evidence that mouse birds evolved six million years earlier than it was previously thought, according to Ksepka.
In New Zealand, researches came across a fossilised penguin skeleton, called Waimanu manneringi that is about 60.5 to 61.5 million years old.
“The new bird and Waimanu show that the diversifications of birds were well under-way a few million years after the mass extinction that hit 66 million years ago,” Ksepka stated.
The findings were presented October at the 75th annual Society of Vertebrate Palaeontology conference in Dallas.
Image Source: cdn4.sci