FIGURE 12. Age-frequency distribution of Prodipodomys idahoensis at MNA locality 318: 12.1, based on minimum number of individuals represented by dP4 and P4 in each of six arbitrary tooth-wear stages; 12.2, based on labial crown height of P4s; 12.3, based on lingual crown height of p4s. MNI = minimum number of individuals.