A 16th century mummy discovered in Ecuador could hold the history of the proliferation of rheumatoid arthritis. Identified by scholars as the potential remains of the Franciscan monk Lazaro de la Cruz de Santofimia, Guano's mummy still bears the marks of the disease. Studying him could help researchers better understand how this pathology spread to Europe, then to the rest of the world.Following the track of the diseaseAnthropologist and paleontologist Philippe Charlier, director of the research and teaching department at the Musée du Quai Branly in Paris, recently traveled to Quito to analyse the remains of the mummy and the traces that it has. Perfectly preserved thanks to a cold and dry atmosphere, its tissues are still in perfect condition, allowing an accurate study of the symptoms of the disease.‘It is a common disease now, but its home is in America, before the arrival of Christopher Columbus,’ says Philippe Charlier. ‘Guano's mummy is perhaps the missing link [...] that will allow us to understand how this disease, which was originally American, then became a global disease by hybridisation, by the confrontation between the two worlds.’Identity to be confirmedThe identity of the body remains uncertain, and further studies should help to learn more about this mysterious mummy. ‘Guano's mummy comes within this framework of atypical mummies and atypical deaths, and atypical burials,’ said Philippe Charlier. Indeed, it was discovered after an earthquake in 1949, not in a horizontal but vertical position. It was also without any protection other than the stone walls that surrounded it.Guano's mummy is also wearing a garment that is not traditional to that of a Franciscan friar. This man is indeed dressed in quality clothing that would suggest a higher status. The mysterious remains still have many secrets to reveal to researchers.