Paris: Have you ever wondered why our teeth are so sensitive to pain or even cold drinks? It could be due to the fact that they first evolved for a very different purpose when chewing half a billion years ago, he suggested a study on Wednesday.
The exact origin of the teeth, and for what they were, has proven difficult to achieve for scientists.
It is believed that its evolutionary precursors are hard structures called dentods that did not appear in the mouth but in the external armor of the first fish about 500 million years ago.
Even today, sharks, stripes and catfish are covered with microscopic teeth that make their skin rough as sandpaper.
There are several theories about why these dentations appeared for the first time, including that they protected against predators, helped with movement through water or stored minerals.
But the new study published in Nature magazine supports the hypothesis that were originally used as sensory organs that transmitted nerve sensations.
At first, the main author of the study, Yara Haridy, was not even trying to hunt the origins of the teeth.
On the other hand, the postdoctoral researcher of the University of Chicago was investigating another important question that baffled the field of paleontology: what is the oldest fossil of an animal with a spine?
Haridy asked the United States museums to send him hundreds of vertebrate samples, some so small that they could fit at the tip of a toothpick, so that he could analyze them using a CT scanner.
She began to focus on the dentin, the inner layer of teeth that sends sensory information to the nerves in the pulp.
