An Echidna (IMAGE) GigaScience Caption This photo is an example of the echidna speciesTachyglossus aculeatus that researchers sequenced, providing a nearly gapless genome sequence. This genome was used to investigate the evolution of the monotreme multi-sex-chromosome system for sex determination. Credit Allan Whittome Usage Restrictions No restrictions. License CC0 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.