The skeleton of a tiny prehistoric baby bird may provide clues to scientists learning how avian species first evolved, a new study says.
Dating back to the Mesozoic Era (250-65 million years ago) the chick belongs to a group of early birds called the Enantiornithes, and is one of the smallest bird fossils ever discovered from that era.
Measuring less 2in (5cm) across – smaller than most adults’ little fingers – the little bird was discovered at the Las Hoyas fossil site in Spain.
The researchers who analysed the bird’s skeleton found that it died shortly after its birth, which meant that the fossil held clues about the bird’s early development.
Luis Chiappe, a co-author of the study from the LA Museum of Natural History, said: “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.
“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.”
The lead author of the study into the fossilised Enantiornithes, Dr Fabien Knoll, explained how bone developments suggested different evolutionary traits.
“The evolutionary diversification of birds has resulted in a wide range of hatching developmental strategies and important differences in their growth rate,” said Dr Knoll, from the University of Manchester’s Interdisciplinary Centre for Ancient Life, School of Earth and Environmental Sciences, and the ARAID-Dinopolis in Spain.
“By analysing bone development we can look at a whole host of evolutionary traits.”
The team used “synchrotron radiation” – a particle accelerator used in research – to examine the fossil.
Dr Knoll said: “New technologies are offering palaeontologists unprecedented capacities to investigate provocative fossils.
“Here we made the most of state-of-the-art facilities worldwide including three different synchrotrons in France, the UK and the United States.”