Half-a-Billion-Year-Old Tiny Predator Unveils the Rise of Scorpions and Spiders

Two paleontologists working on the world-renowned Burgess Shale have revealed a new species, called Mollisonia plenovenatrix, which is presented as the oldest chelicerate. This discovery places the origin of this vast group of animals--of over 115,000 species, including horseshoe crabs, scorpions, and spiders--to a time more than 500 million years ago. The findings are published in the prestigious journal Nature on September 11, 2019.