Ancient feather in dinosaur poop reveals clues to bird survival

In Montana, paleontologist David DeMar Jr. discovered a 66-million-year-old coprolite, fossilized dinosaur feces, containing a remarkably preserved feather.

DeMar and colleagues analyzed the specimen, revealing fragments of a hesperornithiform, an aquatic bird related to modern loons, alongside feathers and fish scales. The coprolite likely originated from a Nanotyrannus or young Tyrannosaurus rex that consumed the bird and its last meal.

Researchers used scanning technology to examine the feather, finding it possessed water-repellent qualities and a unique, sponge-like core structure not previously seen in feathers from the Mesozoic Era. They also identified more primitive, fuzzy body feathers within the coprolite. Scientists theorize that these less-developed feathers may have been sufficient for the warmer Mesozoic climate but inadequate to protect the bird during the global winter following the Chicxulub asteroid impact.

The study suggests that better insulation may have helped some birds survive the mass extinction event while hesperornithiforms perished. The preserved feather offers a rare look at the plumage of birds that lived alongside dinosaurs, and researchers believe coprolites represent a valuable, underutilized source of information about ancient ecosystems and food chains.