Lampreys (Lethenteron camtschaticum) (IMAGE) University of Fukui Caption These primitive jawless fish could hold clues to the evolutionary origin of vertebrate heads, as evidenced by detailed embryological analyses. Credit Takayuki Onai from University of Fukui Usage Restrictions Cannot be reused without permission License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.