Comparative anatomy
Edward Tyson is regarded as the founder of modern comparative anatomy. He is credited with determining that whales and dolphins are, in fact, mammals. Also, he concluded that chimpanzees are more similar to humans than to monkeys because of their arms. Marco Aurelio Severino also compared various animals, including birds, in his "Zootomia democritaea", one of the first works of comparative anatomy. In the 18th and 19th century, great anatomists like George Cuvier, Richard Owen and Thomas Henry Huxley revolutionized our understanding of the basic build and systematics of vertebrates, laying the foundation for Charles Darwin's work on evolution. An example of a 20th-century comparative anatomist is Victor Negus, who worked on the structure and evolution of the larynx. Until the advent of genetic techniques like DNA sequencing, comparative anatomy together with embryology were the primary tools for understanding phylogeny, as exemplified by the work of Alfred Romer.
Francesco Rizzoli
Francesco Rizzoli (11 July 1809 - 24 May 1880) was an Italian politician, surgeon and physician, considered one of the fathers of modern orthopedics.
Doctor Joseph Ruggi speaks of him in his 1924 memoirs: "During the intervention he was in such a state that he was screaming like a madman, 
sustaining and railing against his assistants who were confused and upset [...] while the patient, who was awake, shouted from his lungs, unheeded, throwing insults at the surgeon and his assistants."