The position of the Lower–Middle Cambrian boundary, as classically used, is an issue still under discussion by the International Subcommission on Cambrian Stratigraphy (ISCS), and no level has been established yet. At present, there are two oryctocephalid trilobite species–based Global Standard Stratotype-section and Point (GSSP) proposals in the literature, Oryctocephalus indicus and Ovatoryctocara granulata. These two species have not yet been found in the Mediterranean subprovince. For this reason, other correlation tools that approximate these levels are needed.

A complete chronostratigraphy for the Lower and Middle Cambrian Series of Iberia was proposed by Sdzuy (1971a,b). Recently...