Drawing of upper and lower teeth of a shark of genus Lamna (porbeagles).
Date published 1911
Source Encyclopædia Britannica, 11th ed., Vol. 24, p. 807
Author Albert Charles Lewis Gotthilf Guenther; John Graham Kerr Source: https://commons.wikimedia.org/wiki/File:Britannica_Shark_Lamna_Teeth.png