Elegestolepis

Although only known from placoid scales Elegestolepis, along with and, is the oldest confirmed shark known to science. Elegestolepis dates back to about four hundred and twenty million years ago, but some scales that may yet represent another shark ancestor are known from four hundred and fifty million years ago. Although the placoid scales are accepted to be those of a shark, subtle differences in the scales suggest that Elegestolepis itself may have been quite different in appearance to modern sharks.