Oldest known fossil of modern bird found in Maastricht

A fossilized bird skull found in the limestone of Sint-Pietersberg near Maastricht 20 years ago, turned out to be the oldest known fossil of a modern bird found so far. The approximately 66.7 million-year-old skull belongs to an ancestor of chickens, ducks and geese.

The hitherto unknown bird was given the scientific name Asteriornis maastrichtensis, and the nickname "wonder chicken". It had a length of about 30 centimeters, and a weight of about 390 grams. It lived in the time of the dinosaurs, along the coast of a subtropical sea on the site of present-day Limburg. Scientists believe it can provide new insights into the earliest stages of the evolution of modern birds.

The skull was rediscovered last year when the University of Cambridge made a CT scan of the fossil. What at first glance appeared to be just a few bone fragments protruding from a piece of limestone, turned out to be "one of the best-preserved bird fossil skulls ever," study leader Daniel Field said.

It is also the first fossil of a modern bird discovered in the Northern Hemisphere. "This discovery therefore provides the first evidence that Europe played an important role in the early evolutionary history of modern bird," John Jagt, one of the researchers of this fossil and paleontologist at the Natural History Museum of Maastricht, said to science website Scimex.

"At the same time there were also fish-eating birds with teeth. They were found in the Sint-Pietersberg in Maastricht in the same layer as where this skull was found. The toothed birds were a kind of flying mini-dinosaurs," Jagt said to 1Limburg. "But those toothed fish eaters did not survive the meteorite impact of 66 million years ago. The toothless specimens, they could expand afterwards."