Meanwhile, in 1966, Peruvian physician Javier Cabrera Darquea was presented with a stone that had a carved picture of a fish, which Cabrera believed to be of an extinct species. Cabrera's father had begun a collection of similar stones in the 1930s, and based on his interest in Peruvian prehistory, Cabrera began collecting more. He initially purchased more than 300 stones from two brothers, Carlos and Pablo Soldi, who also collected pre-Incan artifacts, and claimed they had unsuccessfully attempted to interest archaeologists in them. Cabrera later found another source of the stones, a farmer named Basilio Uschuya, who sold him thousands more. Cabrera's collection burgeoned, reaching more than 11,000 stones in the 1970s.