A 120 million-year-old fossil of a two-legged Cretaceous period dinosaur has been found in China's Jehol province. The new finding could shed some light on the evolutionary gaps between dinosaurs and birds. Interestingly, the fossil was found about a decade ago but it was not until recently that the study began.
The study which was published in The Anatomical Record revealed that the creature had feathers on its legs and arms that resembled feathers on bird wings. According to the study, the creature had a bony tail which also had two feathers on it.
The study revealed that the skeleton was preserved lying on its left side on a single bedding plane of ﬁnely laminated siltstone. The specimen is complete; only some ribs are missing. Fortunately, the existing thin ventral ribs and gastralia are numerous, well preserved, and in life position, the study stated. However, researchers are still not clear about the reason behind the feathers on the tail.
The study says, "the presence of very long tail feathers in an immature dinosaur may suggest that their primary functions were not ornamental or were at least unrelated to mating. Even if, unlike many birds, the long rectrices grew in a single molt, it is clear that the appearance of these features occurred well in advance of somatic maturity and may have preceded sexual maturity."
According to Ashley Poust, a palaeontologist at San Diego Natural History Museum, the feathers on the legs and arms resembled with adult birds, but it had other features that suggested it was a juvenile. He further added that it is very clear that the dinosaurs were growing feathers in a different way than modern birds.
According to the study, "X-ray radiography using traditional projection radiography and computed axial tomography at Dalian Medical University Hospital was used to test the authenticity of the specimen because initial preparation was not performed in-house. In order to further test the veracity of the feathers, the rock was prepared away from where it was overlying the edges of exposed feathers."
(With inputs from Agencies)