Figure 6.

Box‐and‐whisker plots of Procrustes shape distances between corresponding brains and endocasts within Alligator and Gallus (brain‐endocast difference), for intraspecific brain shape variation within Alligator and Gallus (brain‐shape difference), interspecific brain shape variation between Alligator and Gallus (Alligator‐Gallus brain shape difference), and interspecific endocranial shape variation in extant birds (endocranial shape variation in birds). The pooled coordinate data were re‐aligned with data from extant birds to place all specimens within a single shape space to allow comparison of variation. The brackets indicate significant differences in Procrustes distances between two levels (*P < 0.05, **P < 0.01, ***P < 0.001).