Caracalla, AE28 of Serdica, Thrace.

AVT K M AVR CEV ANTWNEINOC, laureate, draped, cuirassed bust right.
OVLPIAC CERDIKHC, Zeus, laureate, naked upper body, 
chlamys over shoulder, standing left by altar, holding patera 
and sceptre.

Ruzicka 103 var (altar and bust type); Varbanov 2495 (this coin).