Cerebavis cenomanica

Cerebavis (from Latin cerebrum, “brain”, and avis, “bird”) 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 (PIN 5028/2) 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.