Species emerged at a time well before the evolution of trees and lived a semi-aquatic life, scientists say Sign up for our free Health Check email to receive exclusive analysis on the week in health Get our free Health Check email Get our free Health Check email Email * SIGN UP I would like to be emailed about offers, events and updates from The Independent. Read our Privacy notice Giant scorpions, with formidable pincers over 16cm long, once roamed the floodplains of England and Wales , a new