Maps from the medieval and renaissance period depict images of dragons and sea monsters. Chet Van Duzer's book traces their origin.

Atlases from ancient times have shown pictures of bizarre creatures found in the then unexplored areas. But was it only the fear of the unknown that drove the cartographers to depict these fantastic creatures?

A report from Live Science examines Chet Van Duzer's "Sea Monsters on Medieval and Renaissance Maps." Although the drawings appear to be fairytale creatures some seem to be based on actual living animals. Most of the cartographers began by copying the images from illustrated encyclopaedias, according to the report. It was only later that some cartographers started using hybrid creatures that seemed to be part sea animal and part land animal.

Perhaps the fear of the unknown fed into the psyche of the cartographers. Animals considered mundane and ordinary today could have been considered monsters of that era. Whales and Walruses were considered to be monsters.

Van Duzer is said to have traced the origins of the so called sea monsters from "mappa mundi." Maps from medieval Europe may not have been accurate as the maps of today, but they offer an array of sea monsters and other creatures.

Many of the creatures may have been inspired by stories and folk lore. One creature is shown to have a man in the belly of a monster, it has been speculated that this could be a reference to the Jonah and the Whale story from the Bible. Other bizarre creatures include a creature which is part fish and has a head of a chicken.

Madrid manuscript, a Latin version of Ptolemy's Geography is said to be perhaps the only version that contains sea monsters. Van Duzer suspects that this could have been done to increase the sale value of the maps. Giant octopuses have also been depicted. These creatures are seen dragging a ship into the depths of the ocean much like in the Pirate of the Caribbean movies. Large whales mistaken for an island have also been depicted.

The pictures of the giant whale points to the story where a bunch of sailors dropped anchor near a whale and lit a fire on its back, mistaking it to be a small island. The whale in the story dived into the sea after feeling the heat from the fire.

Maps of the 17th century and later did not show sea monsters very prominently and eventually the creatures vanished from the maps altogether.