The Evolution of Avian Intelligence and Sensory Capabilities: The Fossil Evidence

  • Stig A. Walsh
  • Fabien KnollEmail author
Part of the Replacement of Neanderthals by Modern Humans Series book series (RNMH)


Crocodiles and birds are the only living representatives of Archosauria, a once diverse clade of vertebrates that mastered terrestrial, aerial and aquatic environments during the Mesozoic. Because the braincases of archosaurs are largely ossified, the group has particularly benefited from advances in non-destructive visualisation of endocranial structures over the past two decades. Here, we focus on the neurosensory evolution in the avian lineage of the Archosauria, a group in which the Bauplan of most representatives is optimised to accommodate the functional demands of flight. Neurosensory evolution in birds included a trend towards an enlargement of the telencephalon relative to the rest of the brain, an increased vestibular system sensitivity and probably also a widening of auditory frequency range and an increased reliance on visual stimuli. Despite a relatively smooth surface, bird endocasts provide crucial information on the evolution of a critical structure, the Wulst, which underwent significant enlargement during the Cenozoic and is found with highly variable form in all extant birds. With our increasing awareness of avian cognitive capacity and neural structure, the evolution of the brain in the sauropsid lineage represents an increasingly useful comparative tool against which the development of the synapsid lineage brain of primates can be assessed. Current refinements in quantification of brain structures in extant birds are improving the reliability of the information derived from the external surface of endocasts. This, in turn, should result in a better understanding of the palaeoneurology of extinct birds and other dinosaurs.


Bird Dinosaur Neurosensory evolution Wulst Flocculus 



We thank S. Brusatte for kindly making available images of the endocast of Steneosaurus cf. gracilirostris segmented by A. Muir (Edinburgh University) as well as R. Ridgely (Ohio University) for the digital endocast of the indeterminate Spanish lithostrotian. Two anonymous reviewers provided insightful comments. FK’s research was funded by the European Union (PIEFGA-2013-624969); SAW’s research was supported by NERC grant NE/H012176/1.


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© Springer Japan KK 2018

Authors and Affiliations

  1. 1.Department of Natural SciencesNational Museums ScotlandEdinburghUK
  2. 2.Fundación Conjunto Paleontológico de Teruel-DinópolisTeruelSpain
  3. 3.School of Earth and Environmental SciencesUniversity of ManchesterManchesterUK

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