Table 1. Determination of crown formation times for the mandibular left canines of MLD2 and of StW151.

	StW151			MLD2
	Minimum	Maximum	Measured	Minimum	Maximum	Measured
Cuspal daily secretion	6.06	2.64	3.57	6.06	3.00	3.57
rate (CuDSR) [μm/day]
Source	CuDSR DNH35	CuDSR Homo	Mean	CuDSR DNH35	CuDSR Homo	Mean
	South African	sapiens	measured rate	South African	sapiens	measured rate
	Homo molar [61]	canine [68]		Homo molar [61]	canine[68]
Cuspal thickness [μm]		1285			1033
Cuspal formation	212	404	370	171	345	297
time [days]
Number of perikymata		174 (±7)			220 (±13)
Long-period lines		8			7
periodicity[61] [days]
Lateral enamel formation		1392 (±56)			1540 (±91)
time [days]
Crown formation time	1604	1796	1762	1711	1885	1837
[days]		(±56)			(±91)
Crown formation time	4.39	4.92	4.83	4.69	5.16	5.0
[years]		(±0.15)			(±0.25)

The number of perikymata used for calculating the formation time of the lateral enamel is the average of the three observers' means. The true crown formation time of the StW151 LLC will exceed our results since the crown is not fully formed. The lateral enamel formation time was determined from the perikymata counts on the 3D renderings combined with 2D virtual histological slice (for StW151), multiplied by the long period lines periodicity. The cuspal enamel formation time was determined from a linear measurement from the dentine horn tip to the enamel surface at the level of the first perikymata, multiplied by enamel daily secretion rates (see S1 Supporting Information [section III] and S3 Supporting Information).