LIBERO PATRA for PATRI on a denarius of Septimius Severus

[curtislclay]

Wrong letters or omitted letters are very rare on coins of the Severan period struck at Rome.

This one has the added interest of being inexplicable; it's hard to imagine why the engraver wrote PATRA instead of the required PATRI.  He even did it more than once: the four or five specimens of this error that I have observed come from two different reverse dies.

It's not just a grammar mistake, for PATRA is a non-existent form.  No other contemporaneous type had a legend ending in RA; Julia Domna's type at the time seems to have been IVNO REGINA.  Her PRECEDING type, indeed, had been DIANA LVCIFERA, but it's a stretch to imagine that this legend caused the PATRA error in Septimius' next group of types.

Obv. L SEPT SEV PERT AVG IMP VIIII; the normal coin with PATRI is RIC 99 (197 AD). 2.00g, 1h.

[slokind]

And it wasn't a poor engraver; the figures are nice.  It is a weird error, indeed, not to be explained by a native Greek-speaker hired for his figure work, since the -a is just as weird for a Greek.  If they usually discarded errors so serious, this would have to be a die that saw service before it was stopped, rare, as you say.  But the US postal service and mints...  Pat L.