His lecturing career started in 1883 at the Faculty of Philosophy of the University of Zagreb, where he taught paleontology of vertebrates. In 1884 he was appointed assistant, later was associate, and finally full professor, in 1896. In 1893 he became head of the Geological-Paleontological Department of the Croatian National Museum. He was engaged in paleontology, stratigraphy, tectonics, paleoclimatology, applied geology, geological mapping, and hydrography. Gorjanović-Kramberger discovered, described, classified, systemized, aged, and determined environments for numerous new species of fossilized fishes. As a young scientist at the end of the 19th century, he had already published more than fifty works in prestigious European scientific journals.
In 1899 on Hušnjak hill, near the Croatian town of Krapina, he discovered a very rich Neanderthal site of an early man today known as Krapina Man. News of the discovery quickly spread all around Europe and beyond. Gorjanović continued extensive scientific research of osteological human material, fauna, ecological conditions, and the life and culture of people once living in Croatia. While analyzing the finds, he noticed unusually big variations among the bones. With time he realized that evolution was the source of variability which created human individuals of different stature. His analysis and interpretation of fossil remains proved the existence of early humans which he called Homo primigenius, an ancestor of modern man. Later on those finds were classified as Homo neanderthalensis. Gorjanović-Kramberger's research helped prove the theory of evolution of human species, and his theories have influenced the social view of the world. He started the study of skeletons relating to modern humans and developed a technique that analyzes the fluorine in bones to calculate their age. In 1895 he used newly discovered X-rays to analyze inner bone structure. Results of his research related to the finds at Krapina could be found in the monograph "O diluvijalnom čovjeku iz Krapine",, which was published in Wiesbaden in 1906. The publication was the most comprehensive work ever written in the area of the paleontology of man.
Works
In 1909, he founded the Geological Commission for Croatia and Slavonia, with the goal of carrying out geological mapping and research in pedology. The Croatian geological service became independent from the Geological Institute in Budapest and eventually became the present-day Hrvatski geološki institut in Zagreb. Gorjanović-Kramberger published more than 230 papers in Croatian and international journals during his career. He made a couple of geological maps. He was an honorary doctor of the University of Zagreb, a member of the Association of Medical Doctors and Croatian Natural Sciences Association, and an honorary citizen of Zagreb, Karlovac, and Krapina. Gorjanović-Kramberger was a member of nine foreign scientific associations. From 1891, he was an associate member and from 1909 a full member of the then Yugoslav Academy of Sciences and Arts. Gorjanović-Kramberger remained active after his retirement. Between 1899 and 1929, he published 53 works related to discoveries at the Krapina site.
