Stethacanthus – a prickly-finned shark (ste-tha-can-thuss)

Model of Stethacanthus altonensis.
Image: Jon Augier
Source: Museum Victoria

HOW BIG IT WAS

Stethacanthus was about 70 cm long.

This odd-looking shark lived in shallow coastal waters 350 million years ago, feeding on fish, cephalopods and crustaceans. The purpose of the strangely-shaped fin and spiked forehead of Stethacanthus is uncertain – they may have played a role in courtship or as a visual threat.

Source : http://museumvictoria.com.au