Never seen a coin with someone riding possibly a lion backward. The obverse has Emperor Volusian heading right. It weighs 10.66 g. Hope I could find an attribution.
This design was used on many provincials. Here's one from my collection. It's a shame that the goddess's face was affected by some BD (treated), but this coin is scarce and it may be years before I have the opportunity to upgrade it. Julia Domna AD 193-217. Roman provincial Æ 23 mm, 11.12g. Moesia Inferior, Nikopolis ad Istrum, legate Aurelius Gallus, AD 201-203. Obv: IOVΛIA ΔOMNA CE, draped bust right. Rev: VΠ AVΡ ΓAΛΛOV NIKOΠOΛITΩN ΠΡOC ICTΡON, Magna Mater (Cybele) riding lion right, holding scepter and tympanum. Refs: H&J, Nikopolis 8.17.31.1; Varbanov 2894 (same dies); AMNG --; Moushmov --; SNG Copenhagen --; BMC Thrace --; Lindgren --; Mionnet --.
Thank you so much. The coin was struck in Samaria-Judaea. The dude on the lion is reclining left, while the lion is heading right. In the OP coin (mine), the riding god is Dionysus.
This is the Herennia Etruscilla AE29 of Anazarbus showing Dionysos riding the panther. The panther was the animal of choice for this god who would not have felt as comfortable riding Cybele's lion.
Wildwinds lists my coin on the page of Samaria as a Roman colony. In this page, you search Volusian : 1 example.
Are you sure she's riding backward? It looks more to me like she might be riding side-saddle, like Dea Caelestis in this coin -- in other words, that both her legs are on the same side of the lion: Septimius Severus, AR Denarius 203-204 AD, Rome Mint. Obv. Laureate head right, SEVERVS PIVS AVG / Dea Caelestis in headdress riding on lion right, holding thunderbolt & scepter; below, water gushing from rocks left; INDVLGENTIA AVGG; in exergue: IN CARTH [probable reference to water project in Carthage]. RIC IV-1 266, RSC III 222, Sear RCV II 6285. 18x20 mm., 3.9 g.
Gordian III. 238-244 AD. THRACE, Hadrianopolis. Æ (27mm, 10.69 gm, 1h). Obv: AVT K M ANT ΓO-ΡΔIANOC AV, laureate, draped, and cuirassed bust right, seen from behind. AΔΡ-IA-NO-ΠOLEITΩN (ΩΝ ligate), Dionysos reclining left, holding scepter, on Panther walking right. Mionnet Supp. II pg. 329, 778 var. (bust type); Varbanov 4003 (R5); SNG Copenhagen__.
A follow-up question: never mind riding backward or forward, are there Greek or Roman coins (or art in general) showing women -- whether humans or goddesses -- riding horses astride rather than side-saddle? Other than Amazons? (See https://en.wikipedia.org/wiki/File:Amazone_Staatliche_Antikensammlungen_2342.jpg) And not counting Celtic coins? (See https://www.pinterest.com/pin/506303183091266941/.)
