Table 2.

Malleus/incus lever ratio in Paranthropus robustus compared with living hominids

Species*Malleus, manubrium length, mean ± SD, rangeIncus, functional length, mean ± SD, rangeMalleus/incus, lever ratio, mean ± SD, range
Paranthropus robustus (SKW 18)4.413.251.36
Pan troglodytes (n = 41)5.61 ± 0.273.29 ± 0.191.71 ± 0.11
5.06–6.192.98–3.691.46–1.96
Gorilla gorilla (n = 24)6.17 ± 0.403.87 ± 0.251.60 ± 0.13
5.49–6.853.41–4.461.34–1.86
Pongo pygmaeus (n = 7)4.77 ± 0.153.15 ± 0.151.52 ± 0.09
4.64–4.992.84–3.311.41–1.64
Homo sapiens (n = 42)4.94 ± 0.314.01 ± 0.221.23 ± 0.08
 4.22–5.593.61–4.461.02–1.39
  • * Hominid samples restricted to individuals preserving both the malleus and incus.