Big-headed turtle in the stream in Phu Khieo Wildlife Sanctuary-Nam Nao National Park

The big-headed turtle (Platysternon megacephalum) is named after the size of its head which cannot be retracted into its shell. It uses its armoured head, sharp beak, and long sharp claws to defend itself against predators. The species has been classified as critically endangered in the IUCN Red List and is known to inhabit only the forests and inland wetlands of Cambodia, China, Lao PDR, Myanmar, Thailand, and Viet Nam.