Was looking through a Gallienus webpage and ran across this coin. Don't know if plagiarism is the correct term as that replies to copying words. And don't know if the US mint used the image purposely but sure does look similar!! (pictures taken from the internet).
Hardly any image is a new idea anymore. I remember when KY used to have a picture of 2 horses in the middle of the license plate, and someone claimed they had taken a picture that looked like it in the past, so they had to change the design.
Gallienus took his reverse design from a denarius by Decimus Junius Brutus in 48 BC. I would guess there are others. RR denarius, 48BC, Rome Obv - PIETAS behind, bare head of Pietas right. Rev - ALBINVS BRVTI F, clasped hands holding winged caduceus. Crawford 450/2;HCRI 26;Sydenham 942;Postumia 10. Beautiful iridescent tone. The moneyer, Decimus Junius Brutus, is better known to us than are most moneyers as he saw extensive service under Caesar during the Gallic Wars and was later made governor of Transalpine Gaul. Additionally, he was made Caesar's heir should Octavius reject the inheritance. Despite the favor Caesar showed him, he was amongst the conspirators in his assassination (he should not be confused with M. Junius Brutus, however, who was one of the principals of the conspiracy). Ira & Larry Goldberg Coins & Collectibles, Inc. http://www.goldbergcoins.com/
All circulating and most commemorative US coins are variations on Roman themes. Bust of ruler or personification (Liberty) on obverse? The Romans did that. Lettering around the edges? Romans did that also. Dates on the coins? Romans (although according to different calendars). Seated or standing personifications on the reverse? Romans. Buildings? Romans. Busts left, right, facing, jugate? Romans. Eagles? Romans. Wreaths? Chinese. (Haha, just kidding - ROMANS!) And the Romans were inspired by the coinage of earlier Greek cultures, which had come up with all of those themes in one form or another, long before the She-Wolf suckled Remus and Romulus.
I think the Ike dollar obverse looks a lot like Consul Aulus Postumius Albinus on the obv of a coin by a moneyer with the same name in 48BC coin sold by Münzen & Medaillen AG Basel the reverse of the Mercury dime looks like the center of the reverse of a coin by C. Norbanus in 48BC coin sold by ArtCoins Roma s.r.l. I tell kids at our youth auctions that the Ike dollar is the ugliest US coin.