New look at fossils from northern China may show evolution of dinosaurs to birds
Researchers have used advanced imaging technology to learn about the muscle frame of a tiny creature that lived 160m years ago, suggesting it may have flown
Dinosaurs may have developed muscular, webbed wings and powerful legs as they slowly evolved into birds, according to research carried out by Hong Kong and mainland Chinese scientists.
The discovery could shed new light on the origins of birds and feathered flight, the scientists said.
The researchers studied a small feathered dinosaur called Anchiornis, meaning “close to bird”, which was the size of a raven and lived about 160 million years ago.
Fossilised remains of the strange four-winged creature have been found in large numbers in what is now Liaoning province in northern China.
The species filled an important evolutionary gap with its body belonging to dinosaurs, but other features such as a type of feathers and extremely long front limbs having similarities with birds.
The species was discovered in 2009, but many details about the dinosaur remain a mystery, including one lingering question asked by scientists: did the creature walk or fly?
Past studies on the dinosaur’s ability to fly drew clues from its bones and feathers, according to Xu Xing, the discoverer of the species who is based at the Institute of Vertebrate Palaeontology and Paleoanthropology at the Chinese Academy of Sciences.
The latest research published in the journal Nature Communications on Wednesday investigates the muscular profile of the animal for the first time.
Dr Michael Pittman, lead scientist of the study and the head of the Vertebrate Palaeontology Laboratory at the University of Hong Kong, worked with colleagues using new imaging technology to reveal unprecedented details about fossilised remains of the dinosaur.
While previous research used ultraviolet light, Pittman and his team used much stronger lasers to illuminate florescent coatings on the specimens to obtain the outlines of soft tissue, such as muscle.
The membrane might have given the dinosaur more lift in flight to compensate for its relatively weak feathers. The small membranes could also allow the feathery arms to spread out in an attempt to glide.
“It is a posture also found on eagles and albatrosses,” said Professor Wang Xiaoli, another lead author of the paper at the Institute of Geology and Palaeontology at Linyi University in Shandong province.
The scientists said, however, it was still too early to rule conclusively whether the dinosaur ever flew.
The researchers found signs of highly developed muscles on Anchiornis’ long hind legs, which suggested the traits of a capable runner.
“But on the hind legs we also found long, thick feathers good for flying, but cumbersome for running. This is really, really puzzling,” Wang said.
Pittman said the scientists’ findings underscored there was “extensive experimentation” in the slow evolutionary process that led from dinosaurs to birds.
The research community has generally accepted that birds originated from dinosaurs, but questions remains about when it happened and how, with the latest research providing an “important calibration point”, Pittman said.