A particle accelerator and a long-dead fish hold the key to the history behind the human smile.
All living jawed vertebrates have teeth but conventional wisdom stated that the first jawed vertebrates did not have the type of teeth currently seen today and that they captured prey using a scissors-like jawbone. But new research shows that these early creatures had teeth that eventually evolved the same way the jaw did.
The information appears in the October 17 issue of Nature.
The research team studied the jaws and fossils of a primitive fish called Compagopiscis, which was found in Australia. They used high-energy x-rays to determine the evolution of the teeth and bones.
The finding gave the group of paleontologists and physicists the evidence they needed to pinpoint the origin of teeth. The beginnings of teeth were undetermined prior to the study of these primitive fish.
Before researchers had access to the kind of technology currently available, research conducted in this study would have been more challenging and the conclusions would have been less certain.