Several well-preserved arthropod faunas have been studied in Mexico during the past few years. The purpose of the present note is to outline advances in the study of these arthropods and of their paleoenvironmental implications, from four localities. The age for these localities ranges from the Early to the Late Cretaceous. At most of these localities lithographic limestones crop out, with fish remains representing the most attractive element of study. However, arthropods constitute a very important tool for reconstructing paleoenvironment (marine crustaceans, freshwater and terrestrial insects and arachnids). Detailed studies of these assemblages will aid in our understanding of ancient coastal dynamics and the paleoecology of these unique environments.