From Wildlife Extra:
Nagao Kukri snake
October 2012. A new species of snake, Oligodon nagao or the Nagao Kukri Snake, has been discovered in in South East Asia. With about 75 currently recognized species the genus, Oligodon remains one of the largest genera of Asiatic snakes. It is widespread throughout tropical Asia but is especially speciose in the large area known as the Indochinese Peninsula.
Laos, Vietnam & China
Three specimens recently collected in Lang Son and Cao Bang provinces, extreme northern Vietnam, one specimen found in Khammouane Province, central Laos, and the fifth one from extreme southwest Guangxi Autonomous Region, southern China, proved to be morphologically distinct from all other species known from this region. Especially noteworthy is the fact that all these specimens were collected in karst hills. Oligodon nagao is currently known from a small area straddling over Vietnam and China, and from central Laos.
This species has been found only in karst environment. The Vietnamese and Chinese specimens were all collected at night in karst forests. The specimen from Cao Bang was found at night near the limestone cliff surrounded by secondary forest made of short hardwood, shrubs and vines. No water was observed in the vicinity. The Laotian specimen was collected in a large cave of a karst massif located in the corridor connecting Phou Hin Boun National Park to Nakai Nam Theu National Park. The Oligodon specimen did not attempt to bite when it was collected but it showed the usual behaviour of many species of the genus Oligodon when they feel threatened, i.e. showing the bright colour of the ventral side of its tail curled in a spiral.
The paper was published in Zootaxa.