Mercury did not appear among the numinous di indigetes of early Roman religion. Rather, he subsumed the earlier Dei Lucrii as Roman religion was syncretized with Greek religion during the time of the Roman Republic, starting around the 4th century BC. From the beginning, Mercury had essentially the same aspects as Hermes, wearing winged shoes and a winged hat (petasos), and carrying the caduceus, a herald's staff with two entwined snakes that was Apollo's gift to Hermes. He was often accompanied by a cockerel, herald of the new day, a ram or goat, symbolizing fertility, and a tortoise, referring to Mercury's legendary invention of the lyre from a tortoise shell.