Around 430 to 360 million years ago, fierce-looking armored fish called placoderms roamed the world's oceans. Most illustrations show them with jaws and teeth. But whether or not they actually had what we'd now describe as teeth has long been the subject of intense debate among scientists.
Now, using a particle-accelerator called a synchrotron, a UK-led team of researchers from the University of Bristol has discovered that these early jawed fish did indeed have pearly gnashers. And probably sharp ones at that.