Watch List notes:

The Roman Empire
Octavian, as Augustus 27 BC – 14 AD

Denarius, Colonia Patricia 18 BC, AR 3.85 g. CAESARI – AVGVSTO Laureate head r. Rev. Slow quadriga r. containing aquila and surmounted by four miniature galloping horses. C 274. BMC 392. RIC 108a. CBN 1178.
Rare


Ex P. & P. Santamaria, Rome 14 October 1949, Magnaguti, 392; Münzhandlung Basel, 22 March 1937, 535 and UBS 78, 2008, 1314 sales.

This coin likely still relates to the return of the Parthian standards. The temple of Mars Ultor is variously shown with: just the standards; a standard being held by Mars Ultor; and the standards being inside a quadriga; in each case this image being inside the temple itself. Again we must assume that this was an evolving concept as the temple itself had yet to be built. Sadly, after the temple's dedication in 2 BC, we get no coinage showing the end result. This coin is a splendid example for the issue. MSG.