Megachelicerax

Megachelicerax is an extinct genus of stem-chelicerate that lived in Utah during the middle Cambrian. It contains only a single species; Megachelicerax cousteaui. As the oldest known arthropod to bear chelicerae, Megachelicerax is significant in the evolutionary history of chelicerates, as it represents an important transitional stage between stem-group chelicerates like Habeliida and members of Euchelicerata.