Birds' brain may hold clue why they outlived other dinosaurs

US researchers have discovered a new bird fossil which showed that a unique brain shape may be the reason why the ancestors of living birds survived the mass extinction that claimed all other known dinosaurs 66 million years ago.

A team from the University of Texas at Austin, the US, discovered the fossil, which is nearly 70 million years old and has a nearly complete skull -- a rare occurrence in the fossil record that allowed the scientists to compare the ancient bird to birds living today. The team published the findings in the journal Science Advances.

The fossil is a new specimen of a bird named Ichthyornis, which went extinct at the same time as other non-avian dinosaurs and lived in what is now Kansas during the late Cretaceous period. Ichthyornis has a blend of avian and non-avian dinosaur-like characteristics, including jaws full of teeth but tipped with a beak. The intact skull let Torres and his collaborators get a closer look at the brain.

"Living birds have brains more complex than any known animals except mammals," said lead investigator Christopher Torres, who conducted the research while at the UT College of Natural Sciences.