The Pinarii, another patrician family, was also believed to have used the praenomen Mamercus, although no examples from this gens have been preserved.
However, in his history of Rome, Titus Livius records that the gens was still more ancient, and predated the founding of the city.
[5] According to Festus, the praenomen Mamercus was derived from the name of the god Mamers, who was worshipped throughout Italy in pre-Roman times, and was particularly associated with the Oscans.
Since classical times, scholars have postulated that Mamers was the Oscan form of Mars, although the names Marcus and Mamercus frequently existed side-by-side.
Whatever the case, Mamercus is generally believed to have been an Oscan praenomen that was brought to Rome during the reign of Numa Pompilius, if not earlier.