Sea scorpions and true scorpions are actually sister clades that both belong to a Subphylum known as Chelicerata, an ancient group of arthropods that first appeared in the oceans of the Cambrian Period.
海蝎子和真蝎子实际上是姊妹进化枝， 都属于被称为螯肢动物亚门的亚门，这是一种最早出现在寒武纪海洋中的古老节肢动物群。