Asteriornis maastrichtensis: Meet Wonderchicken, Bird from Final Part of Dinosaur Era

Tuesday, March 24, 2020

Asteriornis maastrichtensis is the first modern bird from the age of dinosaurs found in the northern hemisphere. Image credit: Philip Krzeminski.

A new species of ancient bird has been identified from a nearly complete, three-dimensionally preserved skull and associated bones found in Belgium. A detailed analysis of the skull shows that it combines landfowl- and waterfowl-like features, suggesting that the bird is close to the last common ancestor of modern chickens and ducks.

Nicknamed the Wonderchicken and scientifically named Asteriornis maastrichtensis, the prehistoric bird lived 66.75 million years ago (Cretaceous period).

Its fossilized remains were discovered in a limestone quarry near the Belgian-Dutch border.

“The moment I first saw what was beneath the rock was the most exciting moment of my scientific career,” said Dr. Daniel Field, an evolutionary paleobiologist in the Department of Earth Sciences at the University of Cambridge.

“This is one of the best-preserved fossil bird skulls of any age, from anywhere in the world. We almost had to pinch ourselves when we saw it, knowing that it was from such an important time in Earth’s history.”

“Finding the skull blew my mind. Without cutting-edge CT scans, we never would have known that we were holding the oldest modern bird skull in the world,” said co-author Juan Benito, a researcher in the Department of Earth Sciences at the University of Cambridge and the Department of Biology & Biochemistry at the University of Bath.

The skull of Asteriornis maastrichtensis is clearly recognizable as a modern bird.

It combines many features common to the group that includes living chickens and ducks — a group called Galloanserae.

“The origins of living bird diversity are shrouded in mystery — other than knowing that modern birds arose at some point towards the end of the age of dinosaurs, we have very little fossil evidence of them until after the asteroid hit,” said co-author and Ph.D. student Albert Chen, also from the University of Cambridge and the University of Bath.

“This fossil provides our earliest direct glimpse of what modern birds were like during the initial stages of their evolutionary history.”

The fact that Asteriornis maastrichtensis was found in Europe is another thing which makes it so extraordinary.

“The Late Cretaceous fossil record of birds from Europe is extremely sparse. The discovery of Asteriornis maastrichtensis provides some of the first evidence that Europe was a key area in the early evolutionary history of modern birds,” said co-author Dr. John Jagt, a researcher in the Natuurhistorische Museum Maastricht, the Netherlands.

“This fossil tells us that early on, at least some modern birds were fairly small-bodied, ground-dwelling birds that lived near the seashore. Asteriornis maastrichtensis now gives us a search image for future fossil discoveries — hopefully it ushers in a new era of fossil finds that help clarify how, when and where modern birds first evolved,” Dr. Field added.

The discovery is reported in a paper in the journal Nature.


D.J. Field et al. 2020. Late Cretaceous neornithine from Europe illuminates the origins of crown birds. Nature 579, 397-401; doi: 10.1038/s41586-020-2096-0