Two claims must be kept apart. The claim that a shield fell from heaven and guaranteed Roman supremacy is legend and is treated as such by historians. The claim that the Roman state maintained twelve sacred shields, a priesthood to tend them and an annual rite around them is well attested and historically credible. The shields themselves, however, do not survive, and no securely identified ancile has been recovered, so the artifact is classed as lost rather than extant. What can be said with confidence is institutional: the Salii, the March processions and the standing of the ancilia among the pledges of empire are documented, even though the objects and the story of their heavenly origin cannot be verified.
No physical shield survives, and none could be authenticated against the legendary original even if one did, since the entire point of Mamurius Veturius's eleven copies was to make the true shield indistinguishable from its duplicates. The Ancilia are accordingly classed here as a foundation legend rather than a physical-evidence case: what is verifiable is the Salii priesthood's documented historical existence and their attested ritual practice, not the truth of the shield's fall from the sky. The legend's own internal logic, twelve indistinguishable objects standing in for one authentic original, anticipates by many centuries the modern pattern this atlas records for objects like the crystal skulls, where multiplication itself becomes evidence against, not for, authenticity.