Two wings of baby birds that lived alongside the dinosaurs have been found mummified in tree sap in Burma, BBC reports. The amber fixed around the 99 million-year-old wings preserved intricate details, from color, spots, and stripes, to the fact that the wings had tiny, sharp claws―most likely used to climb trees. In the past, most fossils of feathers discovered from this period were only impressions made in a slab of rock. Using advanced x-ray scanning, scientists discovered that these primitive birds had wing and feather structure similar to birds today, they wrote Tuesday in Nature Communications. The findings could help scientists better understand how birds evolved from their dinosaur ancestors.