For decades, scientists have been trying to piece together the anatomy of a tiny prehistoric worm so weird-looking that they named it Hallucigenia. The stiff spikes on the long-extinct critter’s back were long thought to be legs, while seven pairs of spindly limbs were mistaken for tentacles. On Wednesday a research duo said the creature had not only been reconstructed upside down, but also back to front — they found a pair of eyes and a toothy mouth in what was long thought to be its backside. ‘Prior to our study, a large balloon-like orb at one end of the specimen had been interpreted as an amorphous head,’ said Martin Smith of the University of Cambridge, who co-authored a study published in the journal Nature. ‘We can now demonstrate that this actually wasn’t part of the body at all but a dark stain representing decay fluids or gut contents that oozed out of the anus as the animal was compressed during burial,’ he told AFP by email. Smith and colleague Jean-
