An article published in the journal “Proceedings of the National Academy of Sciences” reports a study on fossil foraminifera dating back to the period before and after the great extinction that wiped out dinosaurs. A team of researchers led by Michael Henehan of the GFZ German Research Center for Geosciences examined in particular the carbon and boron isotopes in the calcareous shells of organisms belonging to the group of foraminifera discovering traces of ocean acidification caused by the impact of huge meteorite that determined that great extinction.