Table 2.

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

Species*	Malleus, manubrium length, mean ± SD, range	Incus, functional length, mean ± SD, range	Malleus/incus, lever ratio, mean ± SD, range
Paranthropus robustus (SKW 18)	4.41	3.25	1.36
Pan troglodytes (n = 41)	5.61 ± 0.27	3.29 ± 0.19	1.71 ± 0.11
	5.06–6.19	2.98–3.69	1.46–1.96
Gorilla gorilla (n = 24)	6.17 ± 0.40	3.87 ± 0.25	1.60 ± 0.13
	5.49–6.85	3.41–4.46	1.34–1.86
Pongo pygmaeus (n = 7)	4.77 ± 0.15	3.15 ± 0.15	1.52 ± 0.09
	4.64–4.99	2.84–3.31	1.41–1.64
Homo sapiens (n = 42)	4.94 ± 0.31	4.01 ± 0.22	1.23 ± 0.08
	4.22–5.59	3.61–4.46	1.02–1.39

^*Hominid samples restricted to individuals preserving both the malleus and incus.