Toronto: In a `monstrous` discovery, scientists in Canada have unearthed the first fossils of a feathered dinosaur ever found in the Americas.
The 75-million-year old fossil specimens, uncovered in the badlands of Alberta, Canada, include remains of a juvenile and two adult ostrich-like creatures known as ornithomimids.
Until now, feathered dinosaur skeletons were recovered exclusively from fine-grained rocks in China and Germany.
The ostrich-like dinosaurs in the original Jurassic Park movie were portrayed as a herd of scaly, fleet-footed animals being chased by a ferocious Tyrannosaurus rex.
However, the new research published in the prestigious journal Science reveals this depiction of these bird-mimic dinosaurs is not entirely accurate, the ornithomimids should have had feathers and wings.
The study, led by paleontologists Darla Zelenitsky from the University of Calgary and Francois Therrien from the Royal Tyrrell Museum of Palaeontology, describes the first ornithomimid specimens preserved with feathers.
"This is a really exciting discovery as it represents the first feathered dinosaur specimens found in the Western Hemisphere," says Zelenitsky, lead author of the study.
"Furthermore, despite the many ornithomimid skeletons known, these specimens are also the first to reveal that ornithomimids were covered in feathers, like several other groups of theropod dinosaurs," Zelenitsky said in a statement.
The specimens reveal an interesting pattern of change in feathery plumage during the life of Ornithomimus.
"This dinosaur was covered in down-like feathers throughout life, but only older individuals developed larger feathers on the arms, forming wing-like structures," says Zelenitsky.
"This pattern differs from that seen in birds, where the wings generally develop very young, soon after hatching."
This discovery of early wings in dinosaurs too big to fly indicates the initial use of feathers was not for flight.
"The fact that wing-like forelimbs developed in more mature individuals suggests they were used only later in life, perhaps associated with reproductive behaviours like display or egg brooding," says Therrien.
The fossils will be on display at the Royal Tyrrell Museum in Drumheller, Alberta.