Some microfossils are arduous to observe with the naked eye in the phosphate mines of the Cloup d’Aural. Researchers collect them thanks to the sieving of the sediment. Among these microfossils, paleontologists have found teeth, bones of micro vertebrates, insects, and remnants of plants. Still little known, these plant traces are observed as fruits, seeds, wood debris, etc. There are up to a dozen plant families in some phosphate mines.