TINY 127-MILLION-YEAROLD FOSSIL HOLDS VITAL CLUES TO BIRD EVOLUTION
It looks like good things really do come in small packages: a baby Enantiornithes fossil the size of a cocktail sausage is helping a team at the University of Manchester to piece together the evolution of modern-day birds.
Enantiornithes were a group of prehistoric birds that lived during the Mesozoic era – the age of the dinosaurs. They were able to fly and looked much like modern birds, save for the fact that they had teeth, as well as clawed fingers on each wing.
The fossil in question was unearthed from the bottom of a lake in Spain several years ago, but recent analysis using high-powered particle accelerators known as ‘synchrotrons’ has enabled researchers to picture the tiny specimen at a submicron level, observing the bones’ microstructures in extremely fine detail. It is around 127 million years old, less than 5cm long and would have weighed less than 10g when it was alive. As the bird died shortly after birth, it provided the team with a rare chance to analyse the bone structure and development of the species.
“The evolutionary diversification of birds has resulted in a wide range of hatchling developmental strategies and important differences in their growth rates,” said Fabien Knoll, who led the research. “By analysing bone development we can look at a whole host of evolutionary traits.”
The researchers found the baby bird’s breast bone was still largely made of cartilage and had not yet developed into hard, solid bone when it died, meaning it wouldn’t have yet been able to fly. This may indicate that it was ‘altricial’, or heavily reliant on its parents’ care at a young age, they say.
“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,” said Luis Chiappe from the Los Angeles Museum of Natural History. “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.”