English: Figure 14: Ontogram of one Tylosaurus sp. (Tsp.), eight Tylosaurus kansasensis (Tk), five Tylosaurus nepaeolicus (Tn), and 16 Tylosaurus proriger (Tp) based on a quantitative cladistic analysis. The ontogram is based on a strict consensus of two trees, each with a length of 145 steps, a CI of 0.40, an HI of 0.60, an RI of 0.60, and an RC of 0.24. Holotypes are indicated by asterisks. Character states that diagnose each growth stage are shown along the main branch, and the exemplar specimens are to the left of the main branch; the most mature individual, identified by the analysis with an artificial adult, is indicated by an arrow. Character states that distinguish the group of mature T. nepaeolicus from the group of mature T. proriger are also shown. The encircled numbers on the nodes are the growth stages, and the numbers below and to the right of them are the bootstrap and jackknife values, respectively (1,000 replicates, <50% not shown). Unambiguous character reversals are shown in red. In the individual analyses, “immature” specimens were recovered in the lower third of the tree, “intermediate” specimens were recovered in the middle third of the tree, and “mature” specimens were recovered in the upper third of the tree. Because all “mature” T. proriger specimens are recovered as more mature than all T. nepaeolicus, the hypothesis of anagenesis in WIS Tylosaurus is supported; additionally, all T. nepaeolicus specimens (except for the holotype) are recovered as more mature than all specimens of T. kansasensis, supporting the hypothesis that T. kansasensis are juveniles (Jiménez-Huidobro, Simões & Caldwell, 2016). Abbreviations: cr, coronoid; d, dentary; DL, dentary length; eccp, ectopterygoid process of the pterygoid; f, frontal; isp, infrastapedial process of the quadrate; LJL, lower jaw length; p, parietal; pm, premaxilla; q, quadrate; ssp, suprastapedial process of the quadrate.