The obverse of this Roman denarius depicts Medusa, a monster of Greek and Roman mythology. Meusa turned anyone who looked at her into stone. She has a coiled snake on either side.
The reverse shows Aurora, the goddess of dawn, leading four horses. According to Roman belief, Aurora renewed herself every morning, moving across the sky and announcing the arrival of the sun god.
The design perhaps alludes to the Julian calendar that was aligned to the sun. The new calendar was introduced by Julius Caesar in 46 BC, and came into effect the following year. The run of the horses symbolized the course of time.