Abstract
Two new fossil assemblages are described from Sin Charoen sandpit exploited in Phimai District, NakhonRatchasima Province, Northeastern Thailand. In this province, vertebrate fossils have been yielded fromthe Miocene to the Pleistocene deposits. The Miocene fauna has been documented in detail by a richfossil record from several localities in Chaloem Phra Kiat District, while the Pleistocene fauna has beenwell studied in Khok Sung sandpit in Mueang Nakhon Ratchasima District. The fossil assemblage fromthe upper section of Sin Charoen sandpit is similar to the Middle Pleistocene fauna of Khok Sung, whichis composed of extinct and extant species of mammals and reptiles. Moreover, the finding of Gavialis cf.bengawanicus and Duboisia santeng demonstrates a strong faunal relationship with Early-Middle Pleistocene faunas of Java (e.g., Trinil). The occurrence of large fluviatile turtles and gharials from Sin Charoensandpit indicates that the past river system was more developed than today and that the Khorat Plateauwas at a lower elevation at the time of deposition. The fossil assemblage from the lower section includestwo rhinocerotids and an advanced form of the genus Stegolophodon and is similar to the Late Miocenefauna found in situ in the sandpits of Chaloem Phra Kiat District