In the above referenced article, methods state that the RFI was calculated as the natural log of the ratio of the square root of 3D occlusal area to the square root of the 2D projected area, but area ratios were, in fact, not logged for RFI calculation. Methods also state that OPCR was calculated with a minimum patch size of three grid points, as in previous studies (e.g., Bunn et al., 2011). However, minimum patch size for OPCR in the above referenced article was set to four. To improve the comparability with other studies investigating this metric, the ranges (R), means (x), and standard deviations (SD) of OPCR values with a minimum patch size of three grid points for the taxa under study are as follows: Aotus, R=47.5–61.375, x=54.326, SD=3.782; Callicebus, R=56.75–80.625, x=68.723, SD=7.001; Pithecia, R=71–105.75, x=87.008, SD=10.805; Chiropotes, R=63–95.75, x=83.677, SD=9.304; Cacajao, R=56.875-88.75, x=72.146, SD=9.568. These errors in the description of methods do not affect patterns of intra- and inter-group variance reported in the original study. Moreover, these new values demonstrate that Pithecia, Chiropotes, and Cacajao have OPCR ranges that exceed the range reported for bamboo lemurs (Bunn et al., 2011), further exemplifying occlusal complexity in pitheciine postcanine teeth.