Mastodon Migration (VIDEO) McMaster University This video is under embargo. Please login to access this video. Caption New research from an international team of scientists suggests that dramatic environmental changes accompanying the shift or melting of continental glaciers played a key role as American mastodons moved north from their southern ranges. Credit McMaster University Usage Restrictions None 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.