Role of ortho-retronasal olfaction in mammalian cortical evolution

J Comp Neurol. 2016 Feb 15;524(3):471-95. doi: 10.1002/cne.23802. Epub 2015 Jun 11.


Fossils of mammals and their extinct relatives among cynodonts give evidence of correlated transformations affecting olfaction as well as mastication, head movement, and ventilation, and suggest evolutionary coupling of these seemingly separate anatomical regions into a larger integrated system of ortho-retronasal olfaction. Evidence from paleontology and physiology suggests that ortho-retronasal olfaction played a critical role at three stages of mammalian cortical evolution: early mammalian brain development was driven in part by ortho-retronasal olfaction; the bauplan for neocortex had higher-level association functions derived from olfactory cortex; and human cortical evolution was enhanced by ortho-retronasal smell.

Keywords: cortex; evolution; human; mammalian; olfaction.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Biological Evolution*
  • Fossils / anatomy & histology
  • Fossils / diagnostic imaging
  • Humans
  • Mammals / anatomy & histology*
  • Mammals / physiology
  • Neocortex / anatomy & histology*
  • Neocortex / physiology
  • Skull / anatomy & histology
  • Skull / diagnostic imaging
  • Smell* / physiology
  • Tomography, X-Ray Computed