Discovery Closes 70-Million-Year Knowledge Gap on Avian Brain Evolution

A newly found fossil has the potential to significantly alter current knowledge regarding the development of modern avian brains and intelligence. Scientists, spearheaded by teams from the University of Cambridge and the Natural History Museum of Los Angeles County, identified this fossilized bird, approximately the size of a starling, originating from the Mesozoic Era, also known as the age of dinosaurs. The research sought to digitally reconstruct the brain of the bird, designated Navaornis hestiae, with the goal of tracing the evolutionary roots of the contemporary avian brain. Dr. Guillermo Navalón, a co-lead author of the investigation, expressed that he was “awestruck” by the “one-of-a-kind” fossil, stating it “lets us fully appreciate the anatomy of this early bird.” The study emphasizes that the skull’s nearly intact preservation renders it among the most crucial discoveries of its type. Navaornis existed roughly 80 million years ago in the region presently known as Brazil, preceding the widespread extinction event that eradicated all non-avian dinosaurs. This fossil bridged a 70-million-year void in the comprehension of avian brain evolution, spanning the period between the 150-million-year-old Archaeopteryx, recognized as the earliest bird-like dinosaur, and present-day birds. Navaornis possessed a cerebrum larger than that of Archaeopteryx, indicating potentially more advanced cognitive abilities compared to the earliest bird-like dinosaurs. Nevertheless, the majority of its brain regions were less developed, implying it had not yet acquired the intricate flight-control systems characteristic of modern birds. Dr Navalón, affiliated with Cambridge’s Department of Earth Sciences, commented: “It was one of these moments in which the missing piece fits absolutely perfectly.” He further stated: “This fossil is truly so one-of-a-kind that I was awestruck from the moment I first saw it to the moment I finished assembling all the skull bones and the brain, which lets us fully appreciate the anatomy of this early bird.” Professor Daniel Field of Cambridge’s Department of Earth Sciences, who served as the senior author for the research, noted that contemporary birds, such as crows and parrots, exhibit some of the most sophisticated cognitive abilities within the animal kingdom. He mentioned that researchers have faced challenges in comprehending the timeline and mechanisms behind the evolution of birds’ distinctive brains and notable intelligence. He appended: “The field has been awaiting the discovery of a fossil exactly like this one.” “This might be just one fossil, but it’s a key piece in the puzzle of bird brain evolution,” he stated. Dr Luis Chiappe, a co-lead author affiliated with the Natural History Museum of Los Angeles County, further indicated that the finding revealed certain birds soaring above dinosaurs possessed a completely modern skull geometry over 80 million years ago. Follow Cambridgeshire news on BBC Sounds, Facebook, Instagram and X. Copyright 2024 BBC. All rights reserved. The BBC is not responsible for the content of external sites. Read about our approach to external linking.