(January 11, 1638 – November 25, 1686) Was a Danish pioneer in both anatomy and geology. In 1659, he decided not to accept anything simply written in a book, instead resolving to do research himself. The consequences of his self-study is that he is the father of geology and stratigraphy. He was responsible for the recognition of geological strata, and the theory that successive layers of geological formations (strata) contained a fossil record of life in chronological order.
He eventually became a tutor to the all powerful De Medici Family, and ultimately, became a Bishop and a strong leader in the Catholic Counter-Reformation. He is largely unknown despite his many great achievements, which may have been due to his religious zeal in a time that was moving away from reasoned science and towards observational science.