1880, Moreno went to France, where he spoke at a meeting of the Anthropology Society of Paris, discussing two prehistoric skulls he had unearthed in Río Negro territory. He believed one was from the Quaternary period, and the other had ritual deformation in a manner similar to the skulls of the Aymara people of the Andes and Altiplano.

After his return to Argentina, that year he embarked on his second major expedition to the territory of Patagonia.