The Sumatran rhinoceros (Dicerorhinus sumatrensis) is one of the most threatened mammals on earth. By 2011, only about 200 of the rhinos were thought to remain living in the wild. Now, an international team of researchers has sequenced and analyzed the first Sumatran rhino genome from a sample belonging to a male made famous at the Cincinnati Zoo. This study reported in Current Biology on December 14 shows that the trouble for Sumatran rhinoceros populations began a long time ago, around the middle of the Pleistocene, about one million years ago.