That's a very nice and
rare coin! It's interesting for the fact that the
portrait is
radiate, quite odd on such a small coin that clearly is not a
dupondius. It's also interesting that the
reverse omits SC. My theory on this coin is that it is actually a token, given away to be exchanged for a measure of grain, based on the
reverse type. I find it quite intriguing the way this coin breaks the rules, and that we cannot say for sure what was it's exact purpose. Great find!