500 million-year-old claw-faced sea monster was a killing machine

if you could dip your head into the oceans of Earth as they appeared 500 million years ago, you might see what looked like a spiny, disembodied claw cruising through the depths while trying to stuff an unfortunate piece of prey into its circular, fang-filled mouth. If you were lucky, you might even see a teeny-tiny baby claw bobbing along behind it.