At about 1,8 – 900,000 mya, Sangiran’s marine environment was changed to swamp environment due to the volcanic material sedimentation. There were some types of Crocodile living at the era, along with other mammals such as hippopotamus, elephant, few bovidae (cow, buffalo and wild buffalo). At the time, Sangiran was still lack of species of animals. Early Man (archaic Homo erectus) started to arrive in Sangiran at about 1,5 mya, inhabiting the river banks in the middle of swamp environment. They have
created cultural material in the form of flakes and chalcedony. (Harry Widianto dan Iwan Setiawan Bimas)
