The four hundred and thirty million-year-old fossil belonged to a group of sea scorpions, some of which had pinching claws and could grow up to three meters long.
These sea scorpions had tails that couldn’t move vertically but were highly mobile horizontally, so they could slash their tails from side to side.
The fossil of the scorpion species, called Slimonia acuminate, was discovered at the Patrick Burn Formation near Lesmahagow, Scotland, and purchased by the Berlin Museum of Natural History in the 1990’s.
The slashing scorpion belonged to a larger group of sea scorpions called eurypterids.
They had thin, flexible bodies and are related to modern scorpions and horseshoe crabs.
‘Our study suggests that sea scorpions used their tails, weaponized by their serrated spiny tips, to dispatch their prey,’ said Walter Persons, a paleontologist at the University of Alberta and the lead author of the study.
Dr Persons and his colleague Dr John Acorn made the case that these sea scorpions attacked and killed their prey with horizontal strikes serrated tail.
The fossil revealed that the scorpion’s tail had spiny tips and was curved strongly to one side.
Unlike lobsters and shrimp which can flip their tails up and down, eurypterid tails couldn’t move vertically and instead move their tails horizontally.
‘This means these sea scorpions could slash their tails from side to side, meeting little hydraulic resistance and without propelling themselves away from an intended target,’ said Dr Persons.
‘Perhaps clutching their prey with their sharp front limbs eurypterids could kill pretty using a horizontal slashing motion.’
Among the likely prey of Slimonia acuminata and other eurypterids were ancient early vertebrates.