Oldest fossils on Earth? New look finds they might just be rocks

WASHINGTON — A new study says what were billed as the oldest fossils on Earth may just be some rocks.

Two years ago, a team of Australian scientists found odd structures in Greenland that they said were partly a leftover from microbes that lived on an ancient seafloor. The tiny structures were said to be 3.7 billion years old.

But different researchers concluded in a study published Wednesday that the structures were likely not fossils.

The Australian scientists defended their work. In a statement, they said the researchers didn't take samples from the same places.