Burial ritual clues found in remote Cambodia are shedding light on the lost history of a little-known mountain-dwelling people, researchers say. Scientists from New Zealand\'s University of Otago say they have accomplished the first radiocarbon dating of unusual jar and log coffin funeral internments on exposed ledges high in southern Cambodia\'s rugged Cardamom Mountains. The mysterious funerary rituals, unlike any other recorded in Cambodia, were practiced from at least A.D. 1395 to A.D. 1650, the university said in a release Wednesday. The period coincides with the decline and fall of the powerful Kingdom of Angkor, which was centered in Cambodia\'s lowlands, researchers said. \"Funeral practices in the Angkor Kingdom and its successors involved cremation rather than anything remotely like those found at sites we are studying,\" Otago researcher Nancy Beavan said. \"This stark difference suggests that, in cultural terms, these unidentified mountain dwellers were a \'world apart\' from their lowland contemporaries.\" Archaeological findings from the sites will offer clues about who these mysterious mountain people were, their culture, trade connections and biological adaptation to the environment, the researchers said.