Mexican Upper Cretaceous rudists (Hippuritida, Bivalvia): Taxonomic, stratigraphic, and geologic data

Analysis of seventy published papers dealing with Mexican Upper Cretaceous rudists, together with consultation of the newest geological maps covering the areas with mentioned rudist fossil localities, evidenced that: a) several among the Turonian-Maastrichtian species mentioned are junior synonymies, nomen nudum, insufficiently described, or have untraceable types. According to modern standards, around sixty species seem acceptable, Antillocaprinidae (12), Hippuritidae (11), Plagioptychidae (9), and Radiolitidae (27). Only three species (Turonian) are common with Eurasia. All the Santonian-Maastrichtian rudists (54) are exclusively American species, either ascribed to Eurasian (9) or to American (21) genera. b) Research on rudists helped to improve the stratigraphy in some areas, and to point out or clear up some geological issues in others. c) The restudy of the geology in some areas, of some rudist collections in museums, and of some rudist groups, are much necessary and must be undertaken.