Read our COVID-19 research and news.

Lida XING

Head of tiny dinosaur found trapped in amber

*Update, 23 July, 12:35 p.m.: The paper this story describes has been retracted. The retraction notice states that the description of the specimen is correct. However, another specimen, which has not yet been published, provides some evidence that the animal may have been an unusual lizard, rather than a birdlike dinosaur.

This tiny head, 14 millimeters long (including the beak), belongs to one of the smallest dinosaurs ever found. Entombed in amber for nearly 100 million years, the creature belonged to the group of dinosaurs that gave rise to modern birds. The animal was probably about the size of the bee hummingbird, the smallest living bird.

The fossil, discovered in Myanmar, has been christened Oculudentavis khaungraae, or “eye-tooth bird.” It has large eye sockets on the sides of its head like modern lizards, and its eyes have narrow openings that limit incoming light. That’s a strong hint that the animal was active during the day.

Oculudentavis’s upper and lower jaws are full of sharp teeth—the most found on any ancestral bird—which implies that it was a predator that likely ate insects and other small invertebrates, researchers report today in Nature. They think the species’s tiny size is an example of “island dwarfism,” as it likely inhabited an arc of islands that existed where Myanmar is today.

Without the rest of the body, the scientists can’t tell exactly how Oculudentavis is related to other birdlike dinosaurs—or whether it could fly. But they suspect it belongs to a group of relatively primitive birds, perhaps similar to Archaeopteryx and Jeholornis, species that lived between 150 million and 120 million years ago.