Portrait of Conrad Gesner (or Gessner) Swiss Natural Historian (1516-1565). His major four volume work Historiae Animalium (1551-1558) is considered the beginning of modern zoology. In it he summarised knowledge of quadrupeds, birds and fishes. He illustrated (mainly with the artist Lucas Schan) many of the species he described. His illustrations include fantastic monsters, the first recognised fossils, as well as now extinct animals like aurochs. Gesner added more recent observations and reports while citing sources. It was a radical departure. The book became one of the most widely read zoology texts, with influence for over 300 years.