Southeast Asia Philippines. The eastern half of Indonesia and East Timor (east of the Wallace Line) are considered to be biogeographically part of Oceania (Wallacea) due to its distinctive faunal features. New Guinea and its surrounding islands are geologically considered as a part of Australian continent, connected via the Sahul Shelf. The region was already inhabited by Homo erectus from 1,000,000 years ago during the Middle Pleistocene age. "Homo sapiens" reached the region by around 45,000 years ago, having moved eastwards from the Indian subcontinent. Rock art (parietal art) dating from 40,000 years ago (which is currently the world's oldest) has been
Mainland Southeast Asia Thailand, Laos, Cambodia and Vietnam). To the south it forms the Malay Peninsula, on which are located Southern Thailand and Peninsular Malaysia; the latter is variably considered part of Mainland Southeast Asia or separately as part of Maritime Southeast Asia. Mainland Southeast Asia contrasts with Maritime Southeast Asia, mainly through the division of largely land-based lifestyles in Indochina and the sea-based lifestyles of the Malay and Philippine archipelagos, as well as the dividing line between the Austroasiatic, Tai–Kadai, Sino-Tibetan languages (spoken in Mainland Southeast Asia) and Austronesian languages (spoken in Maritime Southeast Asia). The countries of mainland Southeast Asia received