This one isn’t “Republican”, strictly speaking – it belongs to the vague, in-betweensy period typically called “Imperatorial”, but which is not all that well-defined in time. It ends, definitively, with the accession of Augustus to the Imperial throne in 27 B.C. – when, exactly, it starts depends on who you are asking, but this era contains the rules of Julius Caesar, Pompey, Marcus Antonius, The “Triumvirates”, etc.
In fact, this is an issue of Julius Caesar’s, c. 46/5 BC, struck at a mint in Spain. Diademed head of Venus Genetrix right, erote on shoulder / “Gallia” and a Gaulish captive bound, seated at base of trophy – it’s not legible (yet) but it should have “CAESAR” in the exergue. The Gaulish captive may be supposed to represent Vircingetorix
Crawford 468/1, Sydenham 1014; RSC Julius Caesar 13.
Nice find! – that’s the second Caesar denarius your diggers have found recently in addition to all the Republican stuff – you must be on some late 1st century B.C. – or early 1st century AD (pre-invasion) site.

Weight: 3.56 g
Diameter: 17 mm