Assertion: horseshoe crab's history | /r/CapableOf | stretch nearly half a billion years
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text: It was 1963, and a young research fellow at Johns Hopkins medical school was spending the summer on Cape Cod, studying blood coagulation in an animal totally unfamiliar to him – the horseshoe crab, Limulus polyphemus, a catcher’s mitt-shaped creature with an evolutionary history stretching back nearly half a billion years.