Smithsonian Explorers, The Megatherium Club, by Unknown, c. 1862-63, Smithsonian Archives - History Div, Many scientists lived in the Smithsonian Institution Building in its early years. These four young naturalists lived in the building and often collected for the Smithsonian while on exploring expeditions in the mid-nineteenth century. Clockwise from upper left: Robert Kennicott, Henry Ulke, Henry Bryant and William Stimpson. They dubbed themselves the "Megatherium Club" after an extinct giant sloth that had been recently uncovered..