Boxplot showing the distribution of the ratio of the position of the quadratojugal notch of the quadrate. 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 quadrate of Prosaurolophus maximus (MOR 454-6-24-6-2).