Could I ask a question?

Regarding "2.Wonders are many,and nothing is more wonderful then man.
天下奇跡無數，卻無一比人更奇妙。--Sophocles"

I see many occasions that "then" is used instead of "than", I mean, in the work emails from white Americans. It's surprise to see same thing in this sentence.

Could you please shed the light? Thanks!