September 21, 2012
Donald Duck and his feathered friends are dinosaurs say palaeontologists.
WA Museum Palaeontology curator and UWA honorary research fellow Mikael Siversson said 99.9 per cent of palaeontologists regard birds as one of the oldest living dinosaurs to roam the earth, joining turtles crocodiles and lizards.
“Some dinosaurs are more closely related to birds then they are related to other dinosaurs,” Dr Siversson said.
“So strictly speaking, these days palaeontologists classify birds as highly specialised dinosaurs.”
Dr Siversson said that, along with other fossil finds, 125 million-year-old raptor dinosaur fossils from China showed how birds shared traits with dinosaurs.
“Over the last 10 to 15 years we’ve been finding lots of raptor dinosaurs from China … and these raptor dinosaurs, almost all of them had feathers,” he said.
“Some of them had flight feathers, just like a bird, some of them could climb trees and they could then glide from one tree to another, and that’s a feature that’s also unique to birds.”
Dr Siversson told Inkwire a dinosaur fossil found in Argentina a couple of years ago was so well preserved it helped establish a further link between birds and dinosaurs.
“[The fossil] had a beautifully preserved skeleton including a very well preserved wishbone or facular, and that wishbone had these cavities indicating the presence of clavicular air sacs,” he said.
“It appears that dinosaurs, certainly the carnivorous dinosaurs, had exactly the same type of unique breathing systems as birds.
“Dinosaurs are often portrayed as the epitome of evolutionary failure, having completely died out – however these new findings, strongly indicating [that] birds are dinosaurs, are challenging that view.”
Dr Siversson said birds most likely survived mass extinction due to their choice of food.
“At the end of the Cretaceous Period you had this big asteroid hitting earth,” he said.
“There was a huge dust cloud that spread through the atmosphere, and the world experienced darkness, probably for years, knocking out the photosynthesis.
“If you are an insectivore, insects, they will still survive, so there will still be food for insectivores and some of them probably ate seeds like modern birds.
“And again they could still survive a few years since they were insectivores.”
HUMAN INDUCED EXTINCTION
Australian Research Council future fellow Michael Bunce said birds might have survived mass extinction due to their ability to fly.
“If you buy into the whole idea that dinosaurs went extinct because of an asteroid impact event, then clearly animals that move around, small animals that move around, had a selective advantage,” Dr Bunce said.
He said although birds survived the Cretaceous period, many birds have since gone extinct, many due to human involvement.
“Birds go extinct for different reasons,” he said.
“So birds in New Zealand went extinct, half of them, because of human arrival.
“On Mauritius, of course, dodos went extinct because people ate them.”
Photos: Lily Yeang