Fig. 9. A in A new Arctic hadrosaurid from the Prince Creek Formation (lower Maastrichtian) of northern Alaska

Fig. 9. A. Quadratojugal regression analyses. Biplot of the lateral exposure width of the quadratojugal versus dentary length and quadratojugal shown in lateral view of Ugrunaaluk kuukpikensis gen. et sp. nov. Ugrunaaluk kuukpikensis is similar to Edmontosaurus annectens in the lateral exposure width of the quadratojugal, but different from Edmontosaurus regalis. The 95% confidence interval of U. kuukpikensis dentary length is also shown by the bi-directional arrow. When the regressions show statistically indistinguishable slope values but statistically significant differences in elevation, P values are marked with an asterisk. B. Right quadratojugal of U. kuukpikensis (UAMES 4298) from the early Maastrichtian Prince Creek Formation, Alaska, showing how the lateral exposure width is defined.