Boxplot showing the distribution of the ratio between the total length of the humerus and the width of
the lateral surface of the proximal end of the element 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 this angle
was measured, exemplified in a humerus of Tsintaosaurus spinorhinus (IVPP V725). Grey horizontal lines delimit character states.