This has had a ton of threads already.
Chances are that the fossils were originally from Earth anyway.

A top British scientist claims he has found proof that extraterrestrials exist after cracking open a meteorite. Instead of finding an alien like Hollywood favourite ET, Professor Chandra Wickramasinghe discovered the two-inch wide rock was pitted with tiny fossils of algae, similar to the kind found in seaweed. The respected professor believes it proves we are not alone in the universe. He said: “These finds are crushing evidence that human life started outside Earth.” The rock was one of several fragments of a meteorite which crash landed in central Sri Lanka in December.