A preserved fossil bird from the Mesozoic Era is providing unprecedented insights into the evolution of avian intelligence. Discovered in Brazil and identified as Navaornis hestiae, this 80-million-year-old bird fossil could hold the keys to understanding the evolutionary development of the modern bird brain, according to a study led by researchers at the University of Cambridge and the Natural History Museum of Los Angeles County.

A Unique Fossil from Ancient Brazil

The study reveals that the fossil, which includes a near-intact skull, offers a rare look at early bird anatomy, marking it as one of the most complete finds of its kind. Discovered by William Nava, Director of the Museu de Paleontologia de Marília, at a site in Presidente Prudente, this specimen appears to have been preserved in dry creek conditions millions of years ago. The research team used advanced micro-CT scanning to digitally reconstruct the bird’s brain, revealing important evolutionary details.

Co-lead author Dr Guillermo Navalón, from Cambridge’s Department of Earth Sciences, told Science Daily that Navaornis as a critical piece in understanding the transition from early bird-like dinosaurs to the sophisticated bird brains seen today. Dr Luis Chiappe, another co-lead from the Natural History Museum of Los Angeles County, stated that Navaornis had a larger cerebrum than the 150-million-year-old Archaeopteryx, an early bird-like dinosaur, suggesting more advanced cognitive capabilities, though it lacked some of the complex brain structures necessary for modern bird flight.

A Missing Link in Avian Evolution

The research, published in the journal Nature, positions Navaornis within a 70-million-year evolutionary gap. This “intermediate” brain structure is believed to have influenced the development of cognitive abilities crucial to modern birds, like advanced problem-solving and social behaviours. Professor Daniel Field, the study’s senior author from Cambridge’s Department of Earth Sciences, said the discovery addresses a long-standing mystery in vertebrate evolution, highlighting how this fossil provides a clearer timeline of brain development from Archaeopteryx to today’s birds.

New Directions for Bird Evolution Research

The researchers hope that further finds from the Brazilian site will uncover additional details about the evolution of birds and their brains. With more studies planned, the team anticipates Navaornis will continue to play a pivotal role in piecing together the evolution of avian intelligence, offering fresh insights into the origins of cognitive abilities among today’s bird species.