A large sea scorpion roamed the China waters almost half a billion years ago and it was definitely one terrifying looking creature. Several bones were unearthed in China’s Xiushan Formation and after extensive analysis it was identified as being an entirely new genus and species of mixopterid eurypterid (sea scorpion).
This new species has been named Terropterus xiushanensis. The creature lived about 435 million years ago during the Llandovery epoch of the Silurian period. Not only is it the first mixopterid from the ancient supercontinent of Gondwana, but it is the oldest one that’s ever been found in the world.
And it was quite large as it measured up one meter in length (3.3 feet). While this may not seem overly big, the majority of today’s sea scorpions measure less than 10 inches in length but some can grow much larger. The Terropterus xiushanensis had a “particularly enlarged prosomal limb III, characterized by a unique arrangement of spines” which I’m sure made it quite scary to other creatures in the waters as it is believed that it was one of the top predators in the Silurian marine ecosystem during a time when there weren’t any big vertebrates to compete with.
Professor Bo Wang, who is from the Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment at the Chinese Academy of Sciences, as well as his colleagues described the sea creature in further detail, “One of the most remarkable eurypterid families is Mixopteridae, whose members are quite large and superficially scorpion-like eurypterids bearing highly specialized anterior appendages.”
They went on to explain its interesting features, “Their second, and especially the third, pair of prosomal limbs are enlarged and very spiny. These limbs were presumably used for prey-capture, and analogies can be drawn with the ‘catching basket’ formed by the spiny pedipalps of whip spiders among the arachnids.”
Unfortunately, not much is known about these sea scorpions because prior to this discovery, there were only four other specimens that were described in two genera that were revealed 80 years ago – these were the “Mixopterus kiaeri from Norway; Mixopterus multispinosus from New York; Mixopterus simonsoni from Estonia; and Lanarkopterus dolichoschelus from Scotland.” “All are Silurian in age and come exclusively from the ancient continent of Laurussia, which constrains our knowledge of the morphological diversity, geographical distribution and evolutionary history of the group.”
While the Terropterus xiushanensis is the first mixopterid found in ancient Gondwana, researchers are hoping to find more of them. Pictures of the Terropterus xiushanensis specimen as well as an image of what the creature would have looked like can be seen here.
The study was published in the journal Science Bulletin where it can be read in full.