Figure 3.

Boxplot comparing architectural gear ratios (AGR) for the superficial anterior (SAT), middle (SMT) and posterior (SPT) temporalis when tufted capuchins fed on high food material property (FMP) items (i.e. popcorn and shelled cashews) and low FMP items (i.e. marshmallow, grapes and cubes of apple pulp). SAT AGRs were lower and SPT AGRs were higher when the animals fed on mechanically challenging foods. SMT AGR values did not differ between foods varying in FMPs (see also electronic supplementary material, table S3). The upper and lower bounds of the boxes correspond with the 25th and 75th percentiles and the whiskers extend 1.5 times the interquartile range in either direction. The median is represented by a horizontal line inside the boxes. Significance (p < 0.05) is indicated by one asterisk.