Chinanews, Haikou, Dec. 6 – Some 400,000 years ago, Hainan Island was still connected with the mainland. At that time, animals such as giant pandas and great apes moved to settle in Hainan through a land bridge, said Huang Wanbo, a researcher at the Institute of Vertebrate Palaeontology and Palaeoanthropology(IVPP) under the Chinese Academy of Social Sciences, the Hainan Daily reported.About 400,000 years ago, all animal species that appeared in Hainan moved to the area through a land bridge presently known as the Qiongzhou Strait, the researcher said.He reached the conclusion after examining the fossils dug from a quarry and a cave at the Changjiang Li Autonomous County. The fossils belonged to 20 animal species.Some five million years ago, Hainan Island took its basic shape under three strong tectonic movements, the Indosinian movement, the Yanshanian movement and the Himalayan movement. At that time, due to an active tectonic movement occurring on the island, volcanoes located from the southern part of the island to Leizhou Peninsula erupted. After the eruption, a basaltic layer was formed, which later changed the island’s geological feature, Huang said.At present, scientists still do not know when the land bridge broke and why it vanished. To answer these questions, scientists may need to make further studies about the fossils and analyzed the earth crust. Also, the question of how land animals evolved on the island and adapted to the new environment is another enigma.