Ancient Claw-Bearing Predator Pushes Spider Origins Back 500 Million Years
Harvard researchers re-examined a Utah fossil, naming Megachelicerax cousteaui as the oldest chelicerate at about 500 million years old, roughly 20 million years earlier than previously known, with distinctive three-segmented chelicerae and a horsehoe crab–like body, pushing back the origin of spiders and kin to the Cambrian.