Ancient dog-size sea scorpion unearthed in China - Livescience.com

Archaeologists recently discovered the remains of this scorpion (Terropterus xiushanensis), which was a eurypterid — an ancient arthropod closely related to modern arachnids and horseshoe crabs, the researchers wrote in the Nov.

Its barbed 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," study co-author Bo Wang from the Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment at the Chinese Academy of Sciences, and colleagues wrote in the new study.

Pedipalps are the front-most appendages of arachnids.

Usually dedicated to transferring sperm from male spiders to female mates, in some arachnids, such as whip spiders, pedipalps have become adapted to snatch prey.

The fearsome beastie lived during the Silurian period, between approximately 443.8 million and 419.2 million years ago.

xiushanensis, is the first discovered belonging to the family Mixopteriade in 80 years, the researchers say.

"Our knowledge of these bizarre animals is limited to only four species in two genera described 80 years ago: Mixopterus kiaeri from Norway, Mixopterus multispinosus from New York, Mixopterus simonsoni from Estonia and Lanarkopterus dolichoschelus from Scotland," Wang and colleagues wrote in the study.

"Our first Gondwanan mixopterid — along with other eurypterids from China and some undescribed specimens — suggests an under-collecting bias in this group," the researchers wrote in their study.