I read it as listing two distinct issues in a elliptic way; to paraphrase, ""BC" on an ancient coin is an absurdity. Even passing that over, Arabic numerals did not exist at the claimed date".
Oh, hm, yes, I think you're right. Not helped by the article lifting the explanation verbatim. I think I heard this joke aloud first, so it hadn't occurred to me that someone saying "a coin marked 54 BC" meant literally "54", but rather, "the number 54, represented in words, or roman numerals, or whatever was in currency[1] at the time."
no subject
no subject
[1] pun :)