The most common directly preserved fossils are unaltered hard parts of a living organism, like shells, teeth, and bones. ... After the remains of an organism have been buried and cemented within sediment, water percolating through the sediment leaches out the fossil. This leaves a cavity in the rock, called a mold.
Answer: I didn’t take the time to research but in my head i’m thinking didn’t we plant something on mars? research that, maybe it was a movie or something but it’s still something.
