Figure 1. Schematic plots a in Sex estimation from morphology in living animals and dinosaurs

Figure 1. Schematic plots a sexually dimorphic sample to explain basic notions. A, a biplot showing the difference between the total and sex-wise regression lines. B, a biplot of a case in which PC1 and 2 are correlated when viewed sex-wise. C, an idealized case of sexual size dimorphism without shape dimorphism. D, an idealized case of sexual shape dimorphism without size dimorphism. E, an idealized mixture of sexual size and shape dimorphism. F, a typically observed mixture of sexual size and shape dimorphism. Blue and red indicate two sexes (specific sex is irrelevant in these theoretical plots).