Researchers in Idaho say they've finally solved a mystery surrounding a 270-million-year-old shark. After a century of guessing, scientists have put a face to the giant animal that once swam the region, back when the Northwest was underwater.
The problem was that sharks are mostly made of cartilage, which doesn't keep well over millennia. So all scientists had from Helicoprion was a curious spiral of thin, serrated blades – which various scientists imagined to be from its dorsal fin, its tale, its nose ...
