Boxplot showing the distribution of the ratio of the length of the precotyloid process of the squamosal 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 variables of this raio were measured, exemplified in a squamosal
of Parasaurolophus walkeri (ROM 768).