Besides spiders, which modern marine arthropod shares a closer evolutionary heritage with sea scorpions within the Chelicerata?

Answer

Horseshoe crabs (Xiphosura)

As members of the Chelicerata subphylum, sea scorpions share an evolutionary link with horseshoe crabs, often evidenced in general body structure.

Besides spiders, which modern marine arthropod shares a closer evolutionary heritage with sea scorpions within the Chelicerata?
animalextinctionclassarthropodscorpion