In A.D. 280, Saturninus, who was governor of Syria, revolted against Probus. The city of Antioch fell for a period and as a result struck no coins. Money was still needed to pay troops fighting the rebellion, so coins were struck in a temporary mint. These coins are differentiated mainly by style from the other Oriental mints of Cyzicus, Antioch and Tripolis. These coins were struck in this 4th Eastern mint only from A.D. 280- 281, until Saturninus was killed by his own soldiers.
Here is a link to the Estiot article; in which she first identified this mint
https://www.academia.edu/29744478/L_Empereur_et_l_usurpateur_un_4e_atelier_oriental_sous_ProbusThe coin below is a great example of this unknown mint, which is eay to pick out with the large eyes and pointy forehead. Many, if not most, have the dot after the workshop
