Navaornis fills a ~70-million-year gap in our knowledge of the evolution of the unique bird brain. Navaornis hestiae (centre) documents a previously unknown intermediate stage in the evolution of the central nervous system between the earliest birds (e.

Birds descended from the dinosaurs, but researchers have known relatively little about how the bird's brain took shape over millions of years. A new fossil sheds light on that mystery.

Researchers unearthed the skull of a previously unknown starling-sized bird species named Navaornis hestiae that was so well preserved they were able to digitally reconstruct its brain and inner ear anatomy based on the shape of the braincase.

Researchers hope the "exquisitely preserved" fossil will cast new light on an enduring mystery in paleontology.

Interestingly, this fossil fills a 70-million-year-long gap in our knowledge between the early bird-like dinosaurs (Archaeopteryx) and modern birds.

An almost perfect intermediate between Archaeopteryxand modern birds has been discovered with its skull preserved in extraordinary three-dimension. To find such an intact fossil bird that dates back to the Mesozoic is almost unheard of,