A fossil of an apparently sleeping dinosaur found in north-eastern China may provide new evidence that dinosaurs had similar behaviour patterns to those later evolved in birds, the British-based magazine Nature reports.
The Mei Long (soundly sleeping dragon) fossil is a young dinosaur curled up in what appears to be a sleeping position typical of birds, the magazine said in its October 14 edition.
The 53cm troodontid fossil was found by Chinese and United States palaeontologists in rock formations dating back an estimated 128-million to 139-million years near Beipiao city in north-eastern China’s Liaoning province.
The find provides ”rare evidence of behaviour in non-avialan dinosaurs that directly relates to stereotypical behaviour seen in extant birds (avians) and not previously predicted in non-avialan dinosaurs”, Xu Xing and Mark Norell said in their report for the magazine.
”The specimen displays the earliest recorded occurrence of the stereotypical sleeping or resting behaviour found in living birds,” Xu and Norell said.
The ”tuck-in” resting posture of birds reduces surface area and conserves body heat, they said.
”From the phylogenetic (evolutionary) position of the fossil, we can tell that the tuck-in behaviour originated in the non-avialan precursors to modern birds.”
The fossil also ”lends support to the theory that the small size of the dinosaur forebears of birds was crucial to their subsequent development of flight”, the magazine said in a press release.
Mei Long is one of several major finds in north-eastern China in recent years.
”This region is fast becoming a treasure trove for dinosaur finds, yielding fossils that tell us about their behaviour as well as their bodies,” it said. — Sapa-DPA