Niels Steno

Timeline

1. 1638–1660Copenhagen · ZealandBorn in Copenhagen, he received medical and anatomical training locally, displaying fine powers of anatomical observation early on, which laid the foundation for his later reputation in the anatomical circles of the Netherlands and France.
2. 1660–1667Leiden, Paris, and Italy · TuscanyIn the 1660s he carried out anatomical research in Leiden, Paris, and elsewhere, discovering important structures such as the parotid duct (Stensen's duct). In 1666 he studied shark teeth fossils in Italy, proposing that fossils are remains of living organisms and that strata are superposed in order of deposition, and in 1669 published 'De solido intra solidum naturaliter contento', laying the foundation of modern stratigraphy.
3. 1667–1686Florence and the Northern European mission · TuscanyIn 1667 he converted to Catholicism in Florence and took vows, thereafter largely abandoning scientific writing, serving as bishop in various parts of Northern Europe and devoting himself to missionary and pastoral work. He died in 1686 near present-day Schwerin, Germany, and was posthumously hailed as a model of a dual career in science and faith.