Cerebavis

Cerebavis is known from just one partial skull, which was first thought to be a fossilized brain.1

Scientists now know the specimen is actually a skull, not a brain, and they used CT scans to see the brain shape inside.2

Cerebavis had no temporal fenestrae, which are openings in the skull behind the eyes. This is a feature of ornithurine birds, not enantiornithines.2

The brain of Cerebavis was more like a modern bird's brain than the brain of Archaeopteryx, an early bird.2

Cerebavis did not have a wulst, a special part of the brain that helps modern birds with vision and touch. This feature had not yet evolved 93 million years ago.2

The skull bones of Cerebavis were very fused together, which is a sign of advanced flight adaptation, similar to modern flying birds.2