Homology ("H" in tan boxes) versus analogy ("A" in pink boxes) of character states shared by extant river dolphins including Pontoporia. Results for parsimony optimizations of nine characters on two trees, parsimony supermatrix (Fig. 5) and ML/Bayesian constraint of morphology (Fig. 6), are shown for all pairwise comparisons between genera of river dolphins. Question marks indicate cases where optimizations and resulting estimates of homology versus analogy were ambiguous. Trees on the right show alternative mappings of character 245 on the two phylogenetic hypotheses: four transitions to the shared river dolphin state (mastoid of petrosal short) for the parsimony tree and three transitions for the ML/Bayesian constrained tree. Note that many extant and extinct taxa have been pruned from the illustrated trees, but all taxa were considered in the actual character optimizations (Figs. 5, 6). Branches are colored as in Fig. 1.