Tooth enamel is the hardest substance produced by our body, composed almost entirely of the mineral apatite (calcium phosphate) deposited on a substrate of three unique enamel matrix proteins. New research suggests that tooth enamel originated in the skin. Researchers from Uppsala University in Sweden and the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in China combined data from paleontology and genomics to arrive at the answer. The study appeared in the journal Nature.

