Calico Vol II list a "unique" so far AV Aureus from Sponsianus struck circa 248AD/ only coin known from him.
Just read the Wikipedia page about him, that's interesting. Does anyone know what the general current consensus is about it? The article says "the reverse (tail) side of the coin appears to be a copy of a Republican denarius struck in 135 BC" which is pretty odd, right? Quick update: I found this CoinTalk thread about it by Ocatarinetabellatchitchix, it's very insightful.
Maybe, they had some old RR AR Denari and put a crude die with that and a badly designed portrait? With some usurpers, its amazing that they produced beautifully designed coins in a very short reign= Laelinus AV Aureus