Here is another letter to Fortean Times (this one from last June) that never made it into print!
In the Bargello Museum in Florence, there is a sculpture by Donatello which appears to depict a lion holding an alien head. Unfortunately, just as I was about to photograph it, I was told by an attendant that I couldn't (despite the fact that other people were happily taking photos of other objects in the museum, and Donatello died before the law of copyright was invented). Hence the only evidence I can provide is a copy of the illustration in the museum guidebook (first picture). What the lion is actually holding is the coat of arms of Florence (a fleur-de-lys on a shield) but it's an alien-head shaped shield, and the two outer petals of the fleur-de-lys are alien-eye shaped petals. Most strikingly, these two outer petals (in the original Donatello version) are darker than the rest of the symbol. This isn't the case in the copy of the statue in the Piazza della Signora (second picture).