And in the USA, also:

> plural plateaus also plateaux

-- https://www.merriam-webster.com/dictionary/plateau

The variant plateaus would be more common in both forks, I think.

> both forks

Ha, that's such a funny way to think of it the differences. And actually quite accurate as a description in the case of American English, since Noah Webster actively rejected the original British spelling.

Yeah, the plurral was also just borrowed straight from French