Figure 5 Comparison of the frequency distributions of phylogenetic and nonphylogenetic synontomorphies in the ontogeny of Tyrannosaurus rex. Growth stage is along the x-axis (corresponding to the numbered nodes of the ontogram in Fig. 2) and number of synontomorphies is along the y-axis. Phylogenetic characters are in solid bars; nonphylogenetic characters are in hollow bars. The frequency distributions of both sets of data follow the same general pattern, aside from the flatter distribution of the phylogenetic synontomorphies relative to the nonphylogenetic synontomorphies and the reversed pattern seen at growth stages 7 and 8. Both types of changes occur throughout the lifespan of T. rex, indicating that ontogeny is not strictly congruent with phylogeny. Full-size DOI: 10.7717/peerj.9192/fig-5