Early Earth was a strange planet, as a new study suggests it was colored purple and smelled of rotten eggs.
In a study published by journal Proceedings of the National Academy of Sciences, scientists found that there was fossil evidence of microbes that ate other microbes, in a form of feeding called heterotrophy.
Because heterotrophs can not make their own organic nutrients, they have to eat other life forms.
"In this study, for the first time, we identify how it was happening and 'who was eating who,'" researcher Martin Brasier said. "In fact, we've all experienced modern bacteria feeding this way, as that's where that 'rotten egg' whiff of hydrogen sulfide comes from in a blocked drain."
The microbes also made the Earth a purple color, since they are colored in a purple hue.
Brasier said the existence of fossils of bacterium called Gunflintia and iron sulfide replacing some of the bacteria's sheaths indicates the Earth was a bacteria-eat-bacteria world.
"Whilst the Gunflintia fossils are only about half as old, they confirm that such bacteria were indeed flourishing by 1,900 million years ago," researcher David Wacey said. "And that they were also highly particular about what they chose to eat."