Humans related to humble mud worm
This brainless mud worm [Xenoturbella] is a long-lost relative of human beings, scientists have discovered. It appears the slug-like creature found living at the bottom of a Swedish lake shares its ancestry with people… Scientists hope studying the worm will give them a better understanding of vertebrate evolution.
When I first read this, I thought it was stating the bleedin' obvious: if you go back far enough, all species have a common ancestor, so of course we're related to Xenoturbella. But what this research apparently shows is that Xenoturbella, like vertibrates, belong to a group called the deuterostomes, making them more closely related to vertibrates (and hence us) than to the bivalve molluscs, to which they were previously thought to be closely related.
I'll shut up now.