Complex sentence: He received hints that the tribe might exist (under the name vaurá) by other Native Americans he encountered on his expedition, and discovered exactly where they existed when given a map of the region by members of the Suyá tribe.
Split into simpler sentences: He received hints that the tribe might exist (under the name Vaurá) by other indigenous peoples that he encountered on his expedition. He discovered exactly where they existed when given a map of the region by members of the Suyá tribe.