On Apr. 23, 2015, an international collaboration that involved researchers from Sweden, the United States, Canada, and Russia announced they had completed genome sequences isolated from two ancient mammoth specimens.

One of those mammoths, representing the last population on Russia’s Wrangel Island, was estimated to have lived about 4,300 years ago. The other specimen, from northeastern Siberia, was about 44,800 years old. The study results were reported in the Cell Press journal Current Biology.