FIGURE 16. Scatter plots of observations by genus on (1, 3) PCA-1 vs. PCA-3; and (2, 4) PCA-2 vs. PCA-3. (1, 2) Spinofenestella, Alternifenestella, and Minilya (see Figure 15.3 for three-dimensional animation); and (3, 4) Exfenestella, Flexifenestella, Anastomopora, and Wjatkella (see Figure 15.4 and Animation 11).