1558 Conrad Gessner Volume 4, Sea Serpents from his \Historia Animalium\". Later hand colouring. Gessner's accounts included creatures which exist, and creatures which we now know do not. There were small sea snakes in the tropics, and eels in colder water, and there must have seemed every chance that much bigger Sea Serpents roamed the deep. Here he pictures a \"Fotenmeershlang\" or \"foetus sea serpent\". It is hard to be sure what creature is actually depicted but the lower may be a banded eel, the upper some sort of deeper sea fish or gulper eel (which occasionally are found dead in shallower waters after upwellings). His accounts were based on first hand reports as well as the \"authorities\" of earlier authors such as Aristotle and Pliny."