Made in Zurich: The World’s First Animal Encyclopedia

In the 16th century, Conrad Gessner set about the remarkable task of cataloging all animals of the then-known continents. Although zoology was largely unexplored, the scholar and city physician of Zurich amassed a prodigious encyclopedia describing over 1,000 animals in words and pictures. In a special exhibition entitled “Creatures from A to Z – The Animal Kingdom of Conrad Gessner (1516-1565),” the Zoological Museum of the University of Zurich shows how Gessner combined contemporary and classical knowledge, and profoundly influenced the development of modern zoology.

Zoological Museum of the University of Zurich
The Zoological Museum of the University of Zurich has dedicated a special exhibition to Conrad Gessner’s comprehensive animal encyclopedia. (Picture: Zoological Museum of the University of Zurich)

Conrad Gessner was a structured yet unorthodox thinker. His unprecedented “Historia animalium” portrayed animals in all their facets: Aside from habitat, behavior, and physiology, he described their vices and virtues – from the busy bee to the selfless pelican. He addressed the God-given right of humans to use animals, from the hunt, to domestication and animal husbandry, not to mention the preparation of animals as food and medicine. An erudite scholar and practitioner, Gessner’s encyclopedia also examines the role of the animal kingdom in literature, art, proverbs, and fables.

A Seminal Reference Work on Animals

The commemorative exhibition celebrates the 500th anniversary of Conrad Gessner’s birth and shows how the scholar applied an ingenious system to structure his extraordinary knowledge of the animal world. Modeling his work on Aristotle’s, Gessner divided the animal kingdom into four main categories: Quadrupeds, amphibians, birds, and fishes. He devoted one volume to each group, listed the animals in alphabetical order, and divided the information on each animal into eight subsections. “This combination of alphabetical order and structured portraits was an innovation that enabled scholars to find specific information quickly and easily within in a vast compendium and then compare it with the entries on various other animals,” says Lukas Keller, Director of the Zoological Museum of the University of Zurich. 

Filling the Knowledge Gaps

In contrast to his contemporaries, Gessner’s aim was not only to critically examine historical works, but also to generate new knowledge. His approach was rigorous: “The scholar should gather all animal texts and drawings – both traditional and contemporary – and observe, dissect, describe, and illustrate the animals himself. This enables the critical examination and clarification of established and new learnings. Then, the scholar should recombine the enormous mass of knowledge and arrange it anew.”

Gifted Illustrator and Networker

With his detailed illustrations, Conrad Gessner set new standards in the depiction of animals. Comprising around 1,000 woodcuts, his magnum opus places as much value on illustrations as it does on text. Gessner was a keen observer who not only used illustrations from artists and other books: He also drew many animals himself; his blackbird – depicted with a small protruding feather and its beak open in song – stands out as exceptionally lifelike. Although he had no means to travel, Gessner maintained an impressive network. By sharing detailed search lists with his correspondents throughout Europe, he was able to amass valuable specimens, such as a lizard skin from an Italian trader and a toucan beak.

A Master in an Era of Great Transition

When Gessner commenced his great endeavor, the nascent discipline of zoology was at a crossroads between the traditions of classical learning and the development of scientific observation. In some entries of his encyclopedia, Gessner trusted his own judgment, in others he deferred to traditional teachings – as made evident by the unicorn in the exhibition. Indeed, the devout Gessner did not rule out the existence of the mythical beast: As the protagonist of many fables, the unicorn was thought to have a place in the divine plan. Of the 25 mythical creatures described in his work, he cast doubt on the existence of 21 of them, but confirmed the reality of the unicorn. It was not until many decades later that his specimen unicorn horn was accurately identified as the tooth of a narwhal.

Seminal Work

The “Historia aminalium” was written in Latin with scholars in mind, and thus long found only in public libraries or in the collections of the wealthy. To increase sales and reduce the price, the bookmaker Froschauer, predecessor of the publishing house Orell Füssli, produced two standard-size illustrated books. Featuring a considerably abridged Latin text, the “Icones animalium” was more accessible and the illustrations more prominent. Thanks to rapid advancements in printing techniques and mass production, the dissemination of knowledge accelerated: Gessner’s illustration of the giraffe in the “Icones” found its way to China, where it appeared in an encyclopedia in 1725.

500th Birthday of Conrad Gessner 

17 March 2016 to 11 September 2016


Throughout 2016, the University of Zurich is celebrating the 500th birthday of Conrad Gessner, the renowned physician, naturalist, and polymath. Diverse events are being held throughout Zurich in honor of his memory and achievements. More information is available at The Zoological Museum of the University of Zurich has dedicated a special exhibition to “Historia animalium,” Conrad Gessner’s comprehensive animal encyclopedia.


Guided Tours

For school classes and groups: From 17 March, on request (

Public tours: 3 April, 17 April, 8 May, 22 May, 5 June, 19 June, 3 July, 17 July, 7 August, 21 August, 4 October at 2:00pm


Family workshops

“500 years of knowledge remixed” (7 years and older)

Visitors can use historical plant illustrations and Gessner's animal drawings to print their own works of art and discover how animals help plants migrate: 3 April, 17 April, 8 May, 22 May, 5. June, 19 June, 3 July, 21 August, 4 October at 2:00pm



“Facetten eines Universums. Conrad Gessner 1516–2016” (The world in all its facets)

Edited by Urs B. Leu and Mylène Ruoss. With contributions from Simona Boscani Leoni, Massimo Danzi, Florike Egmond, Walter Etter, Anja-Silvia Goeing, Daniel Hess, Hildegard Elisabeth Keller, Urs B. Leu, Clemens Müller, Reto Nyffeler, Manfred Peters, Alex Rübel, Mylène Ruoss, Hans-Konrad Schmutz, Berchtold Weber. Forewords by Susanna Bliggenstorfer, Lukas Keller, and Andreas Spillmann.

ISBN 978-3-03810-152-9, NZZ Libro, CHF 30 (available in the museum shop)

“Conrad Gessner (1516–1565)”

Biography by Urs B. Leu, ISBN 978-3-03810-153-6, NZZ Libro, CHF 48 (available in the museum shop)




Zoological Museum of the University of Zurich

Karl-Schmid-Str. 4, 8006 Zurich

Opening hours:

Tuesday to Friday: 9:00am to 5:00pm

Saturday and Sunday: 10:00am to 5:00pm, closed on Mondays