Found a few of this horseshoe crabs on Keyes beach in Hyannis
Multiple dead individuals along the beach.
Small, possibly young?, individual with a carapace width of about 10 cm.
Merostomata is the name given to a grouping of the extinct Eurypterida (sea scorpions) and the Xiphosura (horseshoe crabs). The term was originally used by James Dwight Dana to refer to Xiphosura only, but was emended by Henry Woodward to cover both groups.