Jaroslav Jahn

His teachers included Antonín Frič and Ladislav Čelakovský (publishing on botany in the magazine Vesmir).

He taught geometry briefly at a secondary school before going to the University of Vienna, on the recommendations of O. Feistmantel, E. Suess and K. Kořistka, where he worked as a paleontology assistant in 1892-93.

He served as an assistant to Wilhelm Waagen was also involved in working on Joachim Barrande's Systême silurien du center de la Bohême.

He received a post at the newly-founded Czech Technical University in Brno in 1899 and became a professor of geology and paleontology.

He helped produce a geological map of Moravia and Silesia at the scale of 1:300,000 and worked on stratigraphy, tectonics and paleontology in Bohemia.