Table 4. Statistical comparisons of the SCC orientation between humans, chimpanzees and bonobos.

	Humans	← p →	Chimpanzees	← p →	Bonobos	← p →	Humans
Canal pair	N = 137	H vs C	N = 62	C vs B	N = 61	B vs H	N = 137
ASCC/LSCC*	74.2±4.4°	<0.001	77.0±7.4°	NS	74.8±7.1°	NS	74.2±4.4°
ASCC/PSCC*	111.2±6.4°	<0.001	105.7±7.6°	<0.001	109.5±6.1°	NS	111.2±6.4°
LSCC/PSCC**	88.2±6.2°	<0.001	80.1±10.8°	<0.001	86.9±10.5°	NS	88.2±6.2°
LSCC right/left**	19.7±8.9°	NS	22.0±9.5°	NS	21.3±15.2°	NS	19.7±8.9°
ASCC right/PSCC left**	10.6±5.4°	<0.001	19.2±9.5°	<0.001	12.8±7.8°	NS	10.6±5.4°
ASCC left/PSCC right**	11.4±6.4°	<0.001	18.0±10.6°	<0.001	14.3±9.2°	NS	11.4±6.4°
MSP/ASCC*	34.9±5.1°	<0.001	39.1±5.9°	NS	38.1±4.6°	<0.001	34.9±5.1°
MSP/LSCC*	80.9±5.5°	NS	80.6±6.6°	NS	82.9±8.6°	NS	80.9±5.5°
MSP/PSCC*	145.3±6.2°	<0.001	142.1±8.0°	<0.001	146.1±7.4°	NS	145.3±6.2°
HP/LSCC*	25.9±6.7°	<0.001	23.0±7.2°	<0.001	26.1±7.5°	NS	25.9±6.7°

Angles measurements and angles comparisons between species showing subtle differences between humans and bonobos and marked differences with chimpanzees (NS  =  not significant, H =  humans, B =  Bonobos, C = Chimpanzees). Anterior, posterior and lateral SCC were referred to as ASCC, PSCC and LSCC. (*) parametric tests were used since angular measurements showed normal distribution. (**) non parametric tests were used since angular measurements did not show normal distribution; however parametric tests results were consistent with those of non parametric tests. All angles in degrees.