A new species of ‘monster’ sea scorpion, which is now extinct, has been discovered by a Queensland museum and is believed to have been among the largest predators in the region.

‘This new animal from Theodore was a massive monster, probably over 2 metre in length and had lived in freshwater lakes, or rivers, in the Theodore area,’ the museum said in a statement.

When the museum was alerted to the find, the paleontology team were perplexed and weren’t sure what group of animals it belonged. Queensland Museum used a fossil ‘cold case’ to identify the newest sea scorpion, a species also known as eurypterids.

The fossil is dated to 252 million years ago and is believed to be evidence of the last eurypterid known from anywhere in the world before end-Permian extinction. The fossil was initially brought to the attention of the museum in 2013, after it was discovered in the 1990s by Nick Freeman on his family property in Theodore.

Queensland museum Associate Professor Dr Andrew Rozefelds (pictured) said the ‘fossil case’ was revisted due to Covid-19 lockdowns

‘When the fragmentary specimen came into our collection, it was initially placed in the “Too-Hard Basket” but the closures provided the opportunity to study and reassess some of our fossil collection and this particular fossil had always intrigued me,’ The museum’s Associate Professor Dr Andrew Rozefelds said.

“From initial research I concluded it had to be an arthropod of some sort and the size, ornamentation and occurrence made affinities with eurypterids likely.”

“This is just before the end-Permian extinction event. The eurypterids disappeared, along with other groups of animals, at this time.
This species would have been among the largest predators in the lakes and rivers of the Theodore area.

According to the Yale Peabody Museum, Eurypterids or sea scorpions are a group of extinct chelicerates or arthropods closely related to spiders, scorpions, horseshoe crabs mites, and ticks of today.

Commonly found in rocks of the Silurian age, these animals thrived across the planet for more than 200 million years until their inevitable disappearance 250 million years ago at the end of the Permian.

Sea scorpions are also the only eurypterids that can swim across vast open oceans. With the pterygotid eurypterids, the largest arthropods, reaching lengths of more than eight feet.