Strict consensus of minimum length trees derived from parsimony analysis of the morphological data with implied weighting (k = 3) and relationships among extant taxa constrained to fit the ML/Bayesian analysis of all molecular data (Figure 4A). Lineages that connect extant taxa are colored; river dolphin lineages are red, and other branches are blue. Dotted lines represent fossil lineages and lead to extinct taxa/OTUs (†). Divergence times between extant taxa in the tree are according to the molecular clock analysis of McGowen et al. ; divergences of extinct taxa/OTUs are based on first and last appearances in the fossil record (thick black bars; see Table 2 and Additional file 2: Table S2). Note that all Oligocene or older cetaceans fell outside of crown Odontoceti and outside of crown Mysticeti. The molecular clock divergences among extant taxa  are shown here to contrast with the patterns recorded in the sampling of the fossil record in our study. Cetacean OTUs in bold followed by "- - - -" are associated with paintings to the right.