Kinematic models of appendages (IMAGE) Geological Society of America Caption Kinematic models of appendages on modern analogue species: the whip scorpion Mastigoproctus giganteus (left) and whip spider Heterophrynus elaphus (right). Credit Credit Russell Bicknell and colleagues. Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. License CC BY-NC Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.