Yes, I saw that too. Apparently, when Maxentius left to fight Constantine at the Milvian Bridge (or shortly thereafter), followers buried these totemic items of his imperial might and there they've lain for 1815 or so years, not far (from what I understand of the location) from where the entrance kiosk now is for visiting the Palatine!

Isn't it amazing to think of how many more discoveries will be made in the next, say, 50 years, some of which may help rewrite our understanding of history?