A close-up view of the head and neck of a 120-million-year-old Sinosauropteryx fossil (top) shows imprints around the body that have long been believed to be early versions of feathers.
New analysis of another fossil of this turkey-size dino species (model at bottom) concludes that the features are actually the remains of collagen fibers and that the dinosaur was bald. The work casts a shadow on the popular theory that Sinosauropteryx and other members of the dinosaur group known as therapods are the ancestors of modern birds.