Boxplot showing the distribution of the angle between the proximal slope of the dentary edentulous portion
and the frontal plane of the skull in 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 the two variables of this raio were measured,
exemplified in Lambeosaurus lambei (CMN 8633). Grey horizontal lines delimit character states.