Early Life (IMAGE) Mass Eye and Ear Caption Early life as it is believed to have looked 335 million years ago, well before the age of the dinosaurs. Ancestors of hospital pathogens are now believed to have lived in the guts of these ancient land animals. Credit Mark Witton 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.