When Saturninus that rascally tribune of the very end of second century was a moneyer he chose types that punned on his name.  A pun that is emphasized by the abbreviation of his cognomen. It’s a rather conservative type for a man we don’t generally think of for his conservatism.  Quadrigas had already been recently revived by L. Conelius Scipo Asiaticus [103 BC Mattingly]. and puns too were the fashion of the time.  Compare this bull (= taurus) used by L. Thorius Balbus.  Crawford thinks the bull might be a symbol of Juno on the obverse (see p. 719 n. 8 of vol 2 of RRC). Maybe it is both.  [102 BC Mattingly] Anyway, the interesting thing is the Saturn, Saturninus association. It makes the choice of Saturn for the obverse of the Piso Caepio coin seem a little odd in light of our literary sources: Here’s the Broughton, MRR entry for them under 100BC, Quaestors: We might also note the use of Saturn as an obverse in 103BC [Mattingly], the year of Saturninus’ first Tribunate, by L. Memmius Gallus: Mattingly has Saturninus’ offices as follows:

104 – Quaestor in charge of Grain Supply from Ostia

103 – First Tribunate

101 – Moneyership

100 – Second Tribunate

We usually think of moneyerships being held before these other offices, but the dates of the other offices are well fixed.  So perhaps Saturninus had his ‘out of order’.  Otherwise his coins would need to be slipped back into the series earlier that 104 and that is apparently hard to reconcile with all the rest of evidence.
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