 These artworks are of uncertain origin and may have been created by Otto von Guericke, the German naturalist who first described the "unicorn" remains in his writings, or Gottfried Wilhelm Leibniz, the author who published the image posthumously in 1749.This rendering represents the oldest known illustration of a fossil skeleton.The beginning of the 19th century saw the first paleontological artworks with an unambiguous scientific basis, and this emergence coincided with paleontology being seen as a distinct field of science.