Researchers discover hidden step in dinosaur feather evolution
Paleontologists at University College Cork (UCC) in Ireland have discovered that some feathered dinosaurs had scaly skin like reptiles today, thus shedding new light on the evolutionary transition from scales to feathers.
The researchers studied a new specimen of the feathered dinosaur Psittacosaurus from the early Cretaceous (135–120 million years ago), a time when dinosaurs were evolving into birds. The study shows, for the first time, that Psittacosaurus had reptile-like skin in areas where it didn't have feathers.
The study, published in Nature Communications, was led by UCC paleontologists Dr. Zixiao Yang and Prof. Maria McNamara of UCC's School of Biological, Earth and Environmental Sciences, who teamed with scientists based in Nanjing University (China).
The team used ultraviolet (UV) light to identify patches of preserved skin, which are invisible in natural light. Further investigation of the fossil skin using X-rays and infrared light revealed spectacular details of preserved cellular structure.
Dr. Yang says, "The fossil truly is a hidden gem. The fossil skin is not visible to the naked eye, and it remained hidden when the specimen was donated to Nanjing University in 2021. Only under UV light is the skin visible, in a striking orange-yellow glow.
Studied dinosaur specimen NJUES-10 under natural (upper half) and UV light (lower half) showing the orange-yellow fluorescence of the fossil skin. Credit: Dr. Zixiao Yang
Dr. Zixiao Yang of University College Cork, who discovered that some feathered dinosaurs had scaly skin like reptiles today, thus shedding new light on the evolutionary transition from scales to feathers. (Image credit: Ruben Tapia/UCC TV). Credit: Ruben Tapia/UCC TV.