127 million year-old fossil gives clues about prehistoric birds

One of the tiniest fossils ever found from the Mesozoic Era is giving scientists new insight into how prehistoric birds evolved. The skeleton, which is almost entirely intact, is that of a baby bird dating back around 127 million years ago.

The chick is from a group of prehistoric birds called Enantiornithes. The specimen measures less than five centimeters and  would have only weighed about three ounces when it was alive.

The fossil is very significant because it gives scientists a rare opportunity to analyze the ancient avian creature at a critical stage in life when its skeleton was still forming.

By looking at the animal’s bone tissue formation, or ossification, the researchers can learn a lot about the chick’s young life. The experts can determine, for example, whether the bird could fly or if it stayed with its parents after hatching.

Study lead author Fabien Knoll is a researcher from the University of Manchester‘s Interdisciplinary Centre for Ancient Life (ICAL) and the School of Earth and Environmental Sciences.

“The evolutionary diversification of birds has resulted in a wide range of hatchling developmental strategies and important differences in their growth rates,” said Professor Knoll. “By analyzing bone development we can look at a whole host of evolutionary traits.”

The team used synchrotron radiation to analyze the fossil at a “submicron” level, which allowed the experts to observe the microstructures of the bones in great detail.

“New technologies are offering palaeontologists unprecedented capacities to investigate provocative fossils,” said Knoll. “Here we made the most of state-of-the-art facilities worldwide including three different synchrotrons in France, the UK and the United States.”

The researchers concluded that the chick would not have yet been able to fly, considering that its sternum was still largely made of cartilage instead of solid bone. The patterns of ossification also indicate that this particular group of prehistoric birds may have been more diverse than previously realized.

“This new discovery, together with others from around the world, allows us to peek into the world of ancient birds that lived during the age of dinosaurs,” explained study co-author Luis Chiappe. “It is amazing to realise how many of the features we see among living birds had already been developed more than 100 million years ago.”

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By Chrissy Sexton, Earth.com Staff Writer

Image Credit: Raúl Martín