In 1839 he published Buenos Ayres and the Provinces of the Rio de la Plata, an account of the geology of the Buenos Aires and Río de la Plata region and his findings of mammalian fossils, presenting Megatherium bones which were assembled and exhibited in the Natural History Museum, London.
The sedges and other plants that grow here left behind by the last glacier were the food for mastodons and giant sloths that once roamed the earth.
Several other "Megatherium Clubs" exist; one formed of overseas Smithsonian researchers, yet another only in fiction, supposedly located in London, United Kingdom.