Conrad Gesner (March 26, 1516 - December 13, 1565) was a Swiss botanist and zoologist. Gesner's Historiae Animalium (Studies on Animals) is considered to be the first modern zoological work. This first attempt to describe many of the animals accurately is illustrated with hand-colored woodcuts drawn from personal observations by Gesner and his colleagues. Gesner describes sea creatures in his final volume which was published in 1587, more than 20 years after his death. Gesner places the octopus in an order called "mollis," or "soft creatures," along with the squid, anemone, and jellyfish. He credits the image of the octopus to Guillaume Rondelet.