After this first fundamental publication, a book about the history of zoological classification, published in 1811, he was appointed member of the Bavarian Academy of Sciences. Spix was also appointed the first conservator, now inline with the title director, of the Bavarian zoological collection, considered as the foundation of the Zoologische Staatssammlung München. He published several further works, the most important being a comparative morphology of the skulls of many different animals, including men, primates, reptiles, birds, and others.