Schopf previously described the fossils in the journal Science in 1993, and he confirmed their biological origin in the journal Nature in 2002. However, this is the first study to reveal both how complex the fossils are and to describe exactly what they are. (Schopf’s work also made news in 2015 when he helped discover a deep-sea microorganism that apparently hasn’t evolved in over 2 billion years.)The most recent findings “will probably touch off a flurry of new research into these rocks as other researchers look for data that either support or disprove this new assertion,” said Alison Olcott Marshall, a geobiologist at the University of Kansas in Lawrence who was not involved in the study, in a press release “People are really interested in when life on Earth first emerged,” Valley said in a press release . “This study was 10 times more time-consuming and more difficult than I first imagined, but it came to fruition because of many dedicated people who have been excited about this since day one … I think a lot more microfossil analyses will be made on samples of Earth and possibly from other planetary bodies.”