This is not a new observation, however. According to
Bastien, Buste
monétaire I, p. 275, a
thunderbolt on the shoulder strap occurs with some frequency in other media: he mentions and illustrates in
his plates a statue of
Drusus, a
bust of
Septimius Severus in the
Vatican, a
cameo of
Tiberius in
Vienna, and a
cameo of
Caligula in
New York. The motif is rarer on coins,
Bastien continues: he points to a bronze
medallion of
Antoninus Pius (
Gnecchi pl. 47.1), a bronze
medallion of
Commodus (Gn. pl. 82.3), and a gold multiple of
Constantine II (
his pl. 185.4).
It would be interesting to know who first recognized this motif on coins, and to have a full list of its numismatic occurrences. I suspect it might have been an art historian or armor/clothing specialist who, having seen the
thunderbolt on sculptures and gems, decided to do a
search on coins, and was successful!