Ancient Aquatic Bird Feathers Unearthed Inside 66-Million-Year-Old Dinosaur Coprolite

Paleontologists in Montana have found exceptionally preserved feathers from an ancient aquatic bird inside a large dinosaur coprolite from the Hell Creek Formation. The find includes the first known hesperornithiform feathers and reveals a mix of modern-like waterproof feathers and smaller primitive feathers, suggesting an evolutionary middle ground between living birds and their dinosaur ancestors. The feathers likely came from the same bird that produced the coprolite, possibly a theropod predator (such as Tyrannosaurus Rex or Nanotyrannus), and offer rare insights into predator–prey interactions and feather evolution around the end-Cretaceous extinction. The study by Jingmai O’Connor and colleagues is published in Current Biology.