Boxplot showing the distribution of the ratio between the length of the postacetabular process and that of the
central plate of the ilium, for a sample of iguanodontoidean ornithopods. The inserted smaller graph shows the Bayesian information criterion
(BIC) for various numbers of clusters in which the data can be classified. The photograph shows how the two variable of this ratio were
measured, exemplified in an ilium of Brachylophosaurus canadensis (MOR 794). Horizontal lines delimit character states.