Well, you're the expert. :) But I definitely agree that this looks suspicious; I just checked Google, and literally *every* page that mentions this is a copy of the Wikipedia article on kangaroos, so I'm 99.9% sure it's made up.
And even if it wasn't, it still isn't referenced, and that alone is enough to remove the claim from the article; the criterion for inclusion in Wikipedia, after all, is not truth but verifiability (using reliable sources; naturally, this implies truth, but the opposite does not hold in general).
So... you absolutely did the right thing! :)