Cerebavis cenomanica

Cerebavis is an extinct genus of ornithuran dinosaurs that lived during the middle Cenomanian of the Late Cretaceous period, and is known from a single partial skull found in the Melovatskaya Formation of Volgograd Region in Russia. The skull was initially described as the fossilised brain of an enantiornithean by Russian palaeornithologist Evgeny Kurochkin and colleagues in 2006. Kurochkin and colleagues described Cerebavis as having a notable mixture of ancestral traits, such as a well-developed olfactory system, with derived traits of modern birds like a large cerebrum. At the same time, they identified various unusual and unique features not seen in the brains of reptiles or birds. These include well-developed auditory tubercles on the midbrain, as well as a prominent parietal organ compared to living birds or Archaeopteryx between them.