Despite the long recognition of its distinction from younger Ordovician rocks and older Precambrian rocks, it was not until 1994 that the Cambrian system/period was internationally ratified. After decades of careful consideration, a continuous sedimentary sequence at Fortune Head, Newfoundland was settled upon as a formal base of the Cambrian period, which was to be correlated worldwide by the earliest appearance of "Treptichnus pedum". Discovery of this fossil a few metres below the GSSP led to the refinement of this statement, and it is the "T. pedum" ichnofossil assemblage that is now formally used to correlate the base of the Cambrian.