Eurypterids

A number of rare, near-complete fossils of ‘sea scorpions’, or Eurypterids, have been found in Scotland over the past 150 years.

These animals, now extinct, are found in rocks formed in the Palaeozoic – 445 to 300 million years ago. The most commonly preserved part of the body is the armoured shell; what makes Scottish Eurypterids so important is that far more of the anatomy is present, including what scientists believe to be sensory feelers (rather like those of modern-day spiders). The Scottish fossils have allowed palaeontologists to build up a stronger picture of these giant creatures from hundreds of millions of years ago.

Eurypterids could grow to up to one metre in size – some of the specimens from Lesmahagow in Lanarkshire reach 70 centimetres in length. It is feasible that the scorpions grew to such a size to compete with armoured fish for food and territory. Evidence of a particular species of eurypterid called Hibbertopterus has been found in Fife, near St. Andrews, in the form of a 330 million-year-old trackway. The tracks left by the six-legged water scorpion measure around 6 metres long and a metre wide, making it the one of the largest terrestrial arthropod trackways in the world. The eurypterid made the trackway as it walked across a sandbar, now turned to sandstone. It is one of Scotland’s most important fossil finds of recent years.

Eurypterid - Pterygotus bilobus

Image courtesy Neil Clark, © The Hunterian

Dr Neil Clark

These fossils inspired me to a career in palaeontology. These fossil ‘sea-scorpions’ were the killing machines of the Palaeozoic with their large serrated jaws and grasping claws. Some of the early examples from Lesmahagow were found by amateur collectors – the tradition of amateur collectors finding important fossils continues to this day. This fossil could represent Scotland’s amateur fossils finding heritage.

Dr Neil Clark, Curator of Palaeontology at the Hunterian Museum