FIGURE 13. A-I in The intriguing shapes of the ammonoid whorl

FIGURE 13. A-I) Variation of the predicted whorl area, the whorl width index (WWI=ww/wh), and the imprint zone rate (IZR=iz/wh) considering the first three PCs measured from the virtual models presented in Figure 10. The predicted area has no spatial units. A) Predicted area for PC1 at different PC2 values. Note PC1 has a local maximum depending on the score values of PC2 and PC3. B) Predicted area for PC2 at different PC1 values. C) Predicted area for PC3 at different PC1 values. D) Predicted WWI for PC1 at different PC2 values. E) Predicted WWI for PC2 at different PC1 values. F) Predicted WWI for PC3 at different PC1 values. Note that at low PC1 values changes for the WWI are not noticeable, and only at high PC1 values the changes become significant for PC3. G) Predicted IZR for PC1 at different PC2 values. H) Predicted IZR for PC2 at different PC1 values. I) Predicted IZR for PC3 at different PC1 values.