Table 2.

Crown extension rates for human, chimpanzee, and Neanderthal first molars

Cusp*TaxonMeanNRange
U mp Homo sapiens 5.82145.28–6.66
Pan troglodytes 7.7737.66–7.90
Homo neanderthalensis 7.601
U mb Homo sapiens 5.87134.68–7.47
Pan troglodytes 6.9335.81–7.61
Homo neanderthalensis 8.47 1
L mb Homo sapiens 6.61185.35–7.42
Pan troglodytes 7.9457.07–8.88
Homo neanderthalensis 7.70 1
L ml Homo sapiens 6.30275.07–7.27
Pan troglodytes 8.8258.00–9.43
Homo neanderthalensis 7.68 1
  • Values represent the length of the enamel–dentine junction (EDJ) divided by the cusp-specific crown formation time, followed by the sample size of each cusp (N) and the range (minimum to maximum values).

  • *U, maxillary; mp, mesiopalatal cusp (protocone); mb, mesiobuccal cusp (paracone); L, mandibular; mb, mesiobuccal cusp (protoconid); ml, mesiolingual cusp (metaconid).

  • Estimated using minor reconstruction of dentine horn tip and prenatal enamel equal to mesiopalatal cusp.

  • Calculated using mCT data to virtually section tooth (optimizing for mesial EDJ length); cusp-specific EDJ length was divided by formation times reported in ref. 8 for each cusp.