The discovery of two volumes of notes and drawings by Leonardo da Vinci, later known as Codices Madrid, by the romanist Jules Piccus in the Spanish National Library in Madrid in 1965 was a sensation. Ten years later, Beuys created a series of drawings that refer to these books by Leonardo. His drawings were published as granolithographs in a limited book edition. Beuys’ occupation with Leonardo began in the 1950s, when he invented a "Giocondology", a science of the Gioconda, the Mona Lisa. Beuys sees an approach in Leonardo‘s work that he finds interesting in terms of his own ideas of expansion: “There is a certain model in Leonardo.” (J. Beuys, quote from: Joseph Beuys, Spuren in Italien, Kunstmuseum Luzern, 1979, no p.).
With this print with the suggested or executed animal skulls and the additional inscription "exterminated" and "fossil", Beuys expresses his interest in science. [Eugen Blume]