Phylogenetic results of Physeteroidea, calibrated for geologic time (left) and illustrating changes in body size (right).

<p>The left tree shows the phylogeny with black bars corresponding to the stratigraphic ranges of each taxon. Arrows on the end of black bars indicate lower confidence in stratigraphic boundaries. The right tree shows the evolution of body size in physeteroids, mapping condylobasal length as a proxy for total length, binned by 6 color values.