The
reverse certainly matches Amisos in
Alliance with Nicaea, which is what Jochen has noted. The
reverse, though from different dies, is a direct match to that of FN 40 for
Maximinus Thrax, the only emperor for which this city appears to have formed alliances under. What is needed is a larger image of the
obverse, but I think that I see at least the starting letters AV K G I, then it gets very fuzzy. It is possible to get a better picture. If it turns out to be
Caracalla then that would be a significant historical discovery - an
alliance much earlier than originally thought.
c.rhodes
PS Taking a quick look at RG, where a few busts of
Caracalla are shown, there does not seem to be much of a likeness between cot b's example and those depicted in RG - there
Caracalla is shown bearded with scowling
face.