[Virginia-American]

since no new phyla have emerged in 580 million years

Aren't flowereing plants a phylum?

[That Subliminal Kid]

Are they?

[general_re]

Aren't flowereing plants a phylum?

Why, yes - yes they are. The phylum of angiosperms (two classes of flowering plants - monocots and dicots) are thought to have evolved during the Cretaceous, which would certainly put them much closer than 580 million years ago.