Edestus
The Edestus shark swam the oceans during the Late Devonian to Late Carboniferous more than 300 million years ago. These sharks grew teeth in curved brackets, and they would not shed their teeth as they became worn like today’s sharks. There was only a single row of teeth on each jaw, and the sharp and serrated teeth were like scissoring shears.
These sharks are believed to have swum in all of the world’s oceans during their time on earth. While there are no extant relatives, the helicoprion is believed to be a relative to the Edestus.