Ladies and gentlemen, meet your ancestor - in fact the ancestor of all animal life on Earth - the comb jelly.
Biologist Casey Dunn of Brown University and colleagues used DNA data from various species to determine that the comb jelly (Ctenophore), which emerged some 600 million years ago, is our true ancient ancestor:
Textbook knowledge says that sponges were the first cab off the rank when multicellular life began to diversify. Our study shows comb jellies, which have well-developed tissues and a nervous system, branched off from other animals even before the lowly sponge (which don't have any tissues or nerve cells). This radically changes our understanding of one of the most fundamental steps on the path to modern animals."
If comb jellies branch first, as the new tree shows, then either sponges aren't as primitively simple they seemed (new hypothesis: they could have simplified later) or else comb jellies evolved a complex body plan separately from the rest of us.'