There has been much controversy and confusion concerning the origins of the Easter Islanders. Thor Heyerdahl proposed that the people who built the statues were of Peruvian descent, due to a similarity between Rapa Nui and Incan stonework. Some have suggested that Easter Island is the remnant of a lost continent, or the result of an extra-terrestrial influence . Archaeological evidence, however, indicates discovery of the island by Polynesians at about 400 AD - led, according to legend, by Hotu Matua. Upon their arrival, an impressive and enigmatic culture began to develop. In addition to the statues, the islanders possessed the Rongorongo script; the only written language in Oceania. The island is also home to many petroglyphs (rock carvings), as well as traditional wood carvings, tapa (barkcloth) crafts, tattooing, string figures, dance and music.