Cranial length and life history variables of the specimens used in statistical analyses.

C, cathemeral; D, diurnal; N, nocturnal; CL, average cranial length (prosthion-inion) measured from this sample.
1activity pattern according to Kirk, 2006 [2].
2neonatal mass, gestation length, and weaning age obtained from [50], supplemented by data from other sources [51]–[55].
3This is a 0-day-old T. syrichta. Two additional T. syrichta (one fetal and one 6-day-old) were studied for comparison to this 0-day-old infant. However, they were excluded from statistical analyses due to prematurity or, in the case of the 6-day-old, because the eyes had been removed prior to acquisition.