Fossilized fish skull shakes up the evolutionary history of jaws
415-million-year-old fossil adds to the growing evidence that sharks are not primitive
![Jawed fish tree](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/01/Giles20et20al20figure20Edited.jpg?fit=860%2C460&ssl=1)
Janusiscus schultzei, a 415-million-year-old fish, shared traits with modern sharks and bony fish, suggesting that the common ancestor of both of these aquatic organisms had a bony external skeleton.
K. Trinajstic