127 Million-Year-Old Fossil Holds Clues To Evolution Of Birds

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A fossil of a prehistoric baby bird belonging to the avian group Enantiornithes was found to be 127 million-years-old. The bird’s skeleton is intact, and the specimen is among the smallest fossils dating back to the Mesozoic era, making it crucial in the study of bird evolution.

Based on the fossil imprint from Las Hoyas, a famous paleontological site in Spain, the bird is smaller than a person’s little finger. The ancient avian creature is just five centimeters. The bird seems to have died shortly after birth. This period is critical to analyze the bone structure and the development of the species.

Hence, the fossil will act as a crucial clue to scientists in the process of learning about bone development in prehistoric birds and the evolution of the ancient avian creatures. Based on the fossil alone, researchers can tell if the prehistoric bird can fly right away or if it needs to stay with its parents to survive.

The study’s lead author from the Interdisciplinary Centre for Ancient Life of the University of Manchester, Fabien Knoll, explains the implication of this fossil.

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

Given the size of the bird, it’s difficult to analyze the fossil by the naked eye. The team had to use synchrotron radiation to observe the bone structure of the fossilized prehistoric bird.

Knoll explained how helpful new technology has been to paleontologists who are in the process of investigating fossils. In the study, they made use of different synchrotrons in the U.S., the U.K., and France to analyze the avian fossil and learn more about the evolution of birds.

Among the findings they discovered from the fossil, researchers learned that the ancient bird would not have been able to fly since the breastplate bone or the sternum had not hardened into solid bone and is mainly composed of cartilage.

With the help of the new fossil and other observations involving other enantiornithine birds, the researchers found that the development of the ancient group is more diverse than they first thought.

While the bird may have been unable to fly on its own, it doesn’t necessarily mean that the young of this particular group of ancient avians were altricial or highly reliant on their parents for feeding and care. It’s also possible that the birds can remain independent despite being flightless. This phenomenon, called precocial, is best seen in chickens.


As reported by Phys.org, one of the co-authors of the study, Luis Chiappe, maintains that the study will allow modern man to see what the world was like when ancient birds lived during the age of dinosaurs and peek into the evolution of birds.

“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.”