PARIS - THE discovery of a petite, plant-eating dinosaur with primitive plumage could mean that the dinosaur from which all others evolved had feather-like protrusions, said a study released on Wednesday.
This forces paleontologists to ask a fundamental question: Does the presence of proto-feathers on both main branches of dinosaur evolution mean they originated in a common ancestor?
Or did unrelated feather-like appendages - including those giving rise to modern birds - appear independently, and at a much later dates, in different groups of dinosaurs over the course of evolution?
The answer depends in part on whether Tianyulong's filament-like proto-feathers grew from inside its skin or on top of it - whether, in other words, they are dermal or epidermal, notes Lawrence Witmer of Ohio University.
The find in north-eastern China is a scientific bombshell, further shattering the once axiomatic view that feathered birds and scaly reptiles developed along different evolutionary paths.
Fossils uncovered in China earlier this decade revealed for the first time feathered dinosaurs older than the winged Archaeopteryx predators - long assumed to be the first with plumage - that roamed the Late Jurassic skies some 150 million years ago.
But the new feather-packing dinosaur, dubbed Tianyulong confuciusi, represents an even more radical departure from old paradigms, according to the study, published in the scientific journal Nature.
All dinosaurs fall into one of two large groups that split apart more than 200 million years ago.
The Saurischia group includes the lumbering, long-necked sauropods seen munching tree-tops in the film 'Jurassic Park,' along with the fearsome Tyrannosaurus rex and all primitive birds, including Archaeopteryx.
The second group, Ornithischia, included armoured dinosaurs such as Tricerotps and Stegosaurus, and was not - despite the misleading name - thought to include anything even remotely birdlike.
But Tianyulong, discovered at the Yixian Formation by a team led by Xiao-ting Zhao of the Tianyu Museum of Nature in Shandong Province, falls squarely in this second branch of dinosaur evolution. -- AFP
