FIGURE 31 in Ammonoids and their biozonation across the Santonian-Campanian boundary in north-eastern Coahuila, Mexico

FIGURE 31. Morphometry of lower Campanian Menuites and Pachydiscus. A: WB/WH and U/D against D for Pachydiscus (P.) duelmensis from Tepeyac (red) and Germany (green), the holotype of Pachydiscus jimenezi Renz, 1936 (turquoise) and Pachydiscus paulsoni of Young (1963, grey) and Cobban and Kennedy (1992b, blue). B: WB/WH and U/D against D for Menuites stephensoni from Tepeyac (red) and western Coahuila (Ifrim et al., 2013, black). Morphometric data of Young (1963) are implausible and thus not shown.