Karl Mayer-Eymar

Karl David Wilhelm Mayer-Eymar (29 July 1826 – 25 February 1907) was a Franco-Swiss scientist who studied very old rocks and the creatures that lived long ago. He is best known for organizing the Earth's layers called the Tertiary into 12 clear stages. This helped scientists learn more about our planet's history.

He was born in Marseilles and grew up in St Gallen after his father died. Even as a young boy, he collected fossils from the sea. He studied at the University of Zurich and later worked at the Museum d'Histoire Naturelle in Paris with Charles Henry Dessalines d'Orbigny. In 1858, he moved to the Zurich Polytechnische Hochschule, where he taught and took care of collections.

In 1857, he published a book called Versuch einer neuen Klassifikation der Tertiär-Gebilde Europas, where he described his way of grouping the Tertiary layers. Some of these names, like the Bartonian and Aquitanian, are still used today. He shared his ideas at a big science meeting in London in 1888. His fossil collections are kept at ETH-Zurich, and several sea creatures were named after him in his honor.