Ediacara biota
From Tardis Wiki, the free Doctor Who reference
The Ediacara biota was some of the earliest known complex multicellular organisms to have evolved on Earth. They vanished at the end of the Cambrian period, around 500,000,000 BC.
The Sixth Doctor once discovered Ediacara remains in early 21st century England, after they had been brought through Dominicus' time corridor. (AUDIO: Power Play)
