The body length is 1 meter, and the "sea scorpion" was found in China 430 million years ago

It resembles a scorpion, with a body length of nearly 1 meter, and its appendages have long sharp spines... It is the "star animal" of the Silurian (about 430 million years ago) plate-footed horseshoe crab (sound thick).

Recently, a joint research team of nanjing institute of geology and paleontology of the Chinese Academy of Sciences and other joint research teams found a new genus of plate-footed horseshoe crab in South China: Xiushan phobia. The relevant research results were recently published in the form of a cover paper in the international academic journal Science Bulletin.

The plate-footed horseshoe crab is an important class of arthropods that lived in the Paleozoic Era and is a close relative of the modern arachnid family. Because of its resemblance to a scorpion, it is commonly known as a sea scorpion. The plate-footed horseshoe crab first appeared in the Ordovician, reached the peak of diversity in the Silurian period, and then went into decline, becoming extinct at the end of the Permian.

Mixed-winged horseshoe crab is a family-level taxon in the order Plate-footed horseshoe, and the third pair of appendages of this taxa is highly specialized, with long spines and exaggerated morphology. The unique and highly recognizable appendages of the hybrid-winged horseshoe crab are similar to the whiskers and limbs of the living whip spider, and are believed to be useful for fixing prey, which is a manifestation of the strong predatory ability of the hybrid-winged horseshoe crab.

However, in contrast to its high level of exposure, there has been a lack of in-depth knowledge of such animals, with four species of mixed-winged horseshoe crabs reported, all based on a small number of fossil specimens from the Silurian Ragosaurus, and no new taxa have been found for nearly 80 years.

Under the guidance of researcher Wang Bo, Wang Han, a master's student at the Institute of Southern Ancient Studies of the Chinese Academy of Sciences, and researchers from the Institute of Paleontology and Paleoanthropology of the Chinese Academy of Sciences, the Natural Museum of Berlin, Germany, and the British Museum of Natural History, discovered the Xiushan phobia, which is a new genus of mixed-winged horseshoe crab, which fills the gap of mixed-winged horseshoe crabs in China and even the entire Gondwana continent, and also represents the oldest known fossil record of mixed-winged horseshoe crabs.

The Xiushan horseshoe crab is large, reaching a length of nearly 1 meter. Its third pair of appendages is specialized and enlarged, and it has a high density of hard and long spines on it; the posterior body and tail resemble a scorpion. Based on morphological and phylogenetic analysis, the researchers reconstructed the morphology of the Xiushan crab and determined its phylogenetic location in the plate-footed horseshoe family. Zhang Ye