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.

海蝎和真正的蝎子实际上是姐妹分类， 为螯肢亚门的亚门，这是最早出现在寒武纪时期海洋中的古老节肢动物体。