Cranial Vault Thickness in the Genus Homo


Cranial vault thickness (CVT) has been noted to vary across members of the genus Homo, peaking in Homo erectus and declining more recently. Homo sapiens, for example, have been noted to have particularly thin vaulted crania. However, the variation within and between species has less frequently been investigated. Cranial vaults are also made up of component layers: two cortical and one trabecular (diploë), and the thickness of these layers may vary independently or in predictable ways. The data on variation in CVT in modern H. sapiens and extinct members of the genus Homo are reviewed along with the hypotheses for the purported hypertrophic vaults in H. erectus. The hypotheses include interpersonal violence providing selective pressure for increased CVT, biomechanical pressures from elongated vault shape, allometric scaling, mechanical forces from increased mastication and systemic increases in growth hormones from exercise.

Key Concepts

  • Cranial vaults are made up of three layers: inner and outer layers are cortical or compact bone, which sandwich a middle trabecular layer called diploë.
  • Total cranial vault thickness in modern Homo sapiens may vary with age, sex, bone type or genetic ancestry.
  • Some fossil human ancestors had thicker or thinner cranial vaults than modern humans.
  • There are no clear reasons for why one species or one individual has a thicker vault than another.

Keywords: cranial vault thickness; diploë; cortical bone; fossil hominin; human evolution; biological anthropology

Figure 1. Boxplots of total frontal (a) and parietal (b) thickness in extinct members of the genus Homo and extant Homo sapiens. Significant group median differences between species are listed in Table. TC: Terry Collection. Adapted from Copes 2012 © L.E.Copes.


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How to Cite close
Copes, Lynn E(Jan 2017) Cranial Vault Thickness in the Genus Homo. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0027077]