Scientists have discovered the first complex creatures living a mile or more below the surface of the Earth, unlocking the possibility that similar organisms are elsewhere in the universe, the Washington Post reports. Researchers found the group of nematodes, or roundworms, in water flowing through several gold mines in South Africa. They've nicknamed the creatures the "worms from hell," and likened the discovery to finding "Moby Dick in Lake Ontario."
While nematodes have previously been found deep on the ocean floor, they've typically only been observed within 20 feet of the ground or ocean bed's surface. The ramifications of this new development reach far beyond Earth: It means complex creatures could exist in similar environments previously thought uninhabitable—particularly below the surface of Mars. "What we found shows that harsh conditions do not necessarily exclude complexity," a lead researcher says. "Evolution of Martian life might have continued underground." (Read more nematode stories.)