I have just added this interesting Fel Temp Phoenix to my collection. The mint mark is SMKϚ - the last character looks like an S but I think it is a digamma, so sixth officinae. Cyzicus is a scarce mint for the Phoenix type; I have not been able to find another image of this sixth issue. The Cyzicus coins I have viewed seem to share the same common feature of a quite detailed Phoenix.
AE Half Centenionalis
Constantius II, 337-361 CE
Diameter: 17 mm, Weight: 2.84 grams, Die Axis: 6h
Obverse: D N CONSTANTIVS PF AVG
Diademed and draped bust to right.
Reverse: FEL TEMP REPARATIO
Phoenix standing right on globe, star in field to right.
Mint: SMKϚ (digamma, sixth officinae) star in field: Cyzicus