Petrus Camper was one of the first Enlightenment scholars to be interested in comparative anatomy. He is best known for his theory of prognathism, where, with a line drawn from the chin to the forehead, he suggested that facial angle affected development. As a forerunner of phrenology, he claimed that Europeans demonstrate a facial angle of 80°, whereas African and Asian populations have an angle of 70°, and the orangutan 42–58°. These early deterministic theories were used to support scientific racism in the 19th century.
He also studied the Louis XV’s “Versailles rhinoceros’ in 1777. In 1780 he published drawings in which he compared the skeleton of an Asian rhinoceros with elephant bones. Félix Vicq-d’Azyr, responsible for the first rhinoceros dissection in 1793, wrote a eulogy in his honour.