This book is a contribution to our understanding of the history of rodents in Thailand over the last 3 million years. The author, a scientist in the Paleontology Section of the Department of Mineral Resources of Thailand, carefully analyzed the fossil rodents in 20 caves scattered throughout Thailand. Nine new species and two new general were discovered, but most species tound are still extant. Important changes in the distribution of many of the species point to dramatic changes in climate during the Plio-Pleistocene periods of Thailand and neighboring countries.