Boxplot showing the distribution of the angle of ventral deflection of the rostral edentulous region of the dentary for a sample of iguanodontoidean taxa. 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 this angle was measured, exemplified in
a dentary of Amurosaurus riabinini (AEHM 1/12). Grey horizontal lines delimit character states.