Cerebavis

Cerebavis is a genus of bird that lived during the Middle Cenomanian (late Cretaceous) period, about 122 Ma ago, and is known from a single brain mold found in Volgograd Region in Russia. Once considered most likely a member of the Enantiornithes, it is notable for its unusual brain, which displays some unusual features, including a well-developed olfactory system and large cerebrum, suggesting it had a well-developed sense of smell. In 2015, a reappraisal of the specimen concluded that it belonged to an ornithurine instead of an enantiornithean.