the Head of the Arrow Worm (IMAGE) University of Bristol Caption The head of the arrow worm, Parasagitta elegans. This group of animals are the closest living relatives to Amiskwia. Credit Photo credit: Rafael Martin Ledo/Consejería de Educación de Cantabría Usage Restrictions Single use only - please do not archive License Licensed content 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.