Knorr was not only a gifted painter and engraver, becoming apprenticed to Leonhard Blanc at the age of eighteen, but also a humanist and an enthusiastic palaeontologist. Amongst his other works was the Collection of Natural Wonders and Antiquities of the Earth’s Crust (1755). Knorr was a prominent collector and art dealer and as such became an intermediary between the collectors of cabinets of natural history and those who used these specimens for identification and scientific enquiry. Knorr gained an international reputation for producing works of fine quality and extreme accuracy, and this was one of his most admired productions.