66-Million-Year-Old Feather Found in Dinosaur Coprolite Sheds Light on Bird Extinction

In 2016, a cherry-sized coprolite was unearthed by paleontologist David DeMar Jr. in northeastern Montana, which contained a feather. A study published on September 10 in Current Biology identified two bone fragments from a flightless aquatic bird known as a hesperornithiform. This coprolite, likely originating from a Nanotyrannus or a juvenile Tyrannosaurus rex, housed several feathers, representing the first instance of plumage found in fossilized feces. The main feather, measuring approximately 0.37 inches, shows water-repellent properties and features not previously observed in Mesozoic feathers. Smaller body feathers indicate inadequate insulation against the cold following the Chicxulub impact. Fish scales suggest the bird's final meal. Lead author Jingmai O'Connor emphasizes the feathers' inability to ensure survival during the environmental crisis, while Steven Salisbury and Julia Clarke offer contrasting perspectives on the results.