The evolution of shared character states of river dolphins that are linked to prey capture. Five characters (#s 24, 37, 39, 40, 188) are mapped onto the parsimony supermatrix tree (A; see Fig. 5) and the ML/Bayesian constrained tree (B; see Fig. 6) using delayed transformation optimization. Changes to the states shared by river dolphins are marked by colored bars on branches; character reversals in some taxa are not shown for simplicity. Marine (blue background) versus riverine (brown background) habitat also is optimized onto the two trees. In C, arrows point to characters 24, 37, 39, 40, and 188 in Platanista (left) and Lipotes (right). Dorsal views of skulls and mandibles are shown, and colors for characters are as in A and B.