Supplementary Figure S1. Pictures showing labeled facial regions used for phenotypic identification of sampled hybrids. Callithrix species were distinguished by: (1) color of the lateral sides of the face; (2) coloration in the frontal and back portions of the vertex; (3)  coloration, shape, and volume of the auricular tufts; (4) presence/absence of a white forehead marking; (4) coloration of the orbital region; and (6) coloration of the menton region.