Sea scorpions slashed victims with swordlike tails
New fossil suggests the body part was used for fighting, swimming
![sea scorpion illustration](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2017/05/051017_HT_sea-scorpion_main.jpg?fit=860%2C460&ssl=1)
EN GARDE! Ancient sea scorpions (one illustrated) may have used serrated, swordlike tails for swimming or as weaponry.
NATHAN ROGERS