Paleontologists have determined that a 540-million-year-old fossil of “a hard-shelled, spiky, bum-faced critter that looks all the world like a nightmare version of Pac-Man pitched by filmmaker Guillermo del Toro,” and has no butt is not one of our ancient ancestors.
“We considered lots of alternative groups that Saccorhytus might be related to, including the corals, anemones, and jellyfish which also have a mouth but no anus,” says University of Bristol paleontologist Philip Donoghue, who co-led the study.
That whole ‘no bum’ thing was eventually considered a red herring.
“Weird Creature With No Butt May Not Be Our Ancient Ancestor After All” Nature 8/18/22
Whew! That was a close one!