Ancient Feather Found in Dinosaur Dropping Pushes Back Evolution of Modern Feathers

Key Takeaways

A 66-million-year-old bird feather was discovered in a dinosaur coprolite in Montana.
This feather, the best preserved of its age, pushes back the evolution of modern feathers by 10 million years.
The find suggests that some birds had a mix of primitive and modern plumage, aiding their survival post-asteroid extinction.

Scientists have uncovered a remarkably well-preserved 66-million-year-old bird feather in a dinosaur coprolite, or fossilized droppings, found in Montana’s Hell Creek Formation. This discovery, made in 2016 by David DeMar, Jr., a researcher from the University of Washington, has significant implications for our understanding of feather evolution.

The feather, approximately 9.3 centimeters long, was discovered within a broken coprolite, which also contained fragments of hesperornithiformes, a group of flightless, diving birds related to modern loons and grebes. This find suggests that the feather belonged to a bird that was eaten and partially excreted by a dinosaur.

Jingmai O'Connor, a paleontologist from the Field Museum in Chicago, led the team that analyzed the coprolite using advanced imaging techniques. Their findings revealed that the feather had a water-repellent structure, similar to modern pelicans, and a lightweight, spongy core surrounded by a harder outer layer, typical of modern feathers.

The presence of this feather pushes the evolution of modern feathers back by 10 million years, providing new insights into the evolutionary history of birds. O'Connor notes, 'What is exciting is to push the occurrence of modern feathers into non-modern birds.'

The team also found two fluffy body feathers with loosely arranged branches, similar to primitive feathers found in 100-million-year-old amber. This suggests that the bird had a mix of primitive and modern plumage, which may have given it an advantage in survival post-asteroid extinction.

The discovery challenges the prevailing theory that all birds survived the mass extinction triggered by an asteroid strike 66 million years ago. O'Connor explains, 'Differences in plumage are emerging as a major contributing factor as to why some birds survived while others didn’t.'

This find is particularly significant because it provides evidence that some birds had a 'middle ground' of primitive and modern plumage, which may have allowed them to adapt to the harsh conditions following the asteroid impact. The wing and tail feathers might have allowed for successful diving, while the less advanced body feathers would have been relatively poor insulators, making the animals more vulnerable to the 'winter' that occurred after the asteroid impact.

The research, published in New Scientist, highlights the importance of continued fossil discovery and analysis in understanding the complex evolutionary history of birds and their survival in the aftermath of the asteroid event.