A. (image) Aarhus University Share Print E-Mail Caption Narwhals with their characteristic spiralled tusks in dense pack ice. Credit Photo: ©Paul Nicklen / paulnicklen.com Usage Restrictions None Share Print E-Mail 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.