Inside the Mouth of Earth’s Oldest Bird

Explore

IIf you’ve ever had the misfortune of staring into the gullet of a screeching goose, you know it contains the stuff of nightmares: a thick, barbed tongue surrounded by a series of fleshy, tooth-like protrusions. Today, research published in Innovation about a recently discovered object Archaeopteryx fossil shows that birds acquired their fascinating structures early in their evolution.

THE Archaeopteryx The fossil in question arrived at the Chicago Field Museum in 2022, and chief preparator Akiko Shinya began the painstaking process of removing the limestone to reveal the complete specimen. To ensure no significant parts of the fossil were removed, Shinya used ultraviolet light, which makes fossilized soft tissue glow. It was then that she noticed something strange.

“I remember they called me and said, ‘Jingmai, we found something strange, come look at it,'” study author Jingmai O’Connor said in a statement. “They showed me these little points of light, and I had no idea what we were looking at.”

After consulting texts on bird anatomy, O’Connor understood what they were: oral papillae. “Imagine if the flesh on the roof of your mouth just had rows and rows of tiny fleshy cones, that’s what birds have,” O’Connor said. These structures facilitate feeding by guiding food down the bird’s throat while keeping it away from the trachea.

Read more: “Conjuring Imaginary Creatures”

But that’s not all, the team also discovered a tiny shard of bone in the tongue. “This tiny bone is one of the smallest bones in the body and it indicates that Archaeopteryx had a very mobile tongue, like many birds today,” O’Connor added.

A scan of the head revealed even more secrets: small tunnels in the beak, indicating the spaces where the nerves used to be. Taken together, the articulate tongue, oral papillae, and sensitive, angry beak all point to an overall adaptive drive toward finding and consuming food, and O’Connor thinks he knows why: Although flight confers enormous benefits, it is not without costs, and chief among them is the demand for more energy.

“These findings show a very clear change in the way dinosaurs ate when they began to fly and had to meet the enormous energy demands of flight,” O’Connor explained. “Birds have an extremely efficient digestive system: everything is modified to maximize the efficiency of their diet and the calories they can extract from food. And the digestive system starts with the mouth.”

Although all birds are dinosaurs, not all dinosaurs are birds, and these structures can help researchers draw a clearer line between the two.

“For a long time, there was very little that could really characterize the transition from terrestrial dinosaurs to flying bird dinosaurs,” O’Connor said. “These strange little features in the mouth of Archeopteryx, which are also found in living birds, give us new criteria we can use to determine whether a dinosaur fossil is a bird or not.”

Enjoy Nautilus? Subscribe for free to our newsletter.

Main image: Photographer Delaney Drummond, (c) Field Museum

• Jake Currie

  Published on February 5, 2026

  Jake Currie is a writer based in Brooklyn, New York.