Microbial communities are found living in a variety of habitats both on the surface and in the sub-surface. But a finding reported in Science recently found microbes living in coals 2500 m below the seafloor. What was most unique about these microbes, was their community affinity with those normally found in forest soils. This suggests that these microbial communities, which are now 2500 m below the seafloor, have been an isolated ecosystem since these forest were growing and buried tens of millions of years ago.