New data on recently described rodent species Paulina's Limestone Rat Saxatilomys paulinae Musser, Smith, Robinson & Lunde, 2005 (Mammalia: Rodentia).

Background: Paulina's Limestone Rat Saxatilomys paulinae Musser et al., 2005 was first discovered by Musser et al. (2005) based on specimens from the Khammouane Limestone National Biodiversity Conservation Area (NBCA) in Khammouane Province in central Lao People's Democratic Republic (PDR). This tower karst landscape is part of the Central Indochina Limestone massif, which extends eastward into north-central Vietnam in Quang Binh and Quang Tri Provinces.

New Information: In April 2014, we conducted a rodent survey and collected four (4) whole specimens of Saxatilomys paulinae in Quang Binh province. This is the first record of Saxatilomys paulinae in Vietnam. External and craniodental characteristics of all specimens clearly exhibit the characters of Saxatilomys paulinae as described in Musser et al. (2005)​. The rats are of medium size (HB: 160.3 ± 2.03 mm, T: 192.3 ± 6.69 mm) with some specific morpological characteristics. The external and craniodental measurement of the specimens from Vietnam tend to be larger than those of specimens from Lao. However, this needs to be verified by more studies in future. The habitat of Saxatilomys paulinae in Vietnam is characterized by complicated terrain comprising low karst towers (around 400 m) with steep slopes covered under limestone humid evergreen forest. The forest has been affected by selected timber logging in the past, but still has a complex 4-layer structure. The population of Saxatilomys paulinae in Vietnam is threatened by rodent trapping/snaring and habitat disturbance. More status surveys should be conducted to assess the species distributional range and its population status for undertaking relevant conservation measures.