Limnonectes paulyambuni currently is considered Endemic to Sabah and reports come from Crocker Range, Kinabalu Park, and Maliau Basin. It is sympatric with L. barioensis and L. mocquardi at sites in Crocker Range. The actual separation of the species in a field situation may be difficult due to the scarcity and quantitative nature of subtle morphological differences. More research is needed. 

The species is medium in size. Adults are on average 50 mm in snout-vent length in males, 55 mm ion females.

The new species can be distinguished from its relatives by a unique combination of physical features. The first finger is as long as the second, and the outer edges of the second and third fingers have freely movable, narrow ridges of skin. The tip of the third finger forms a moderately sized disk that is slightly wider than the basal phalanx. The inner and outer webbing of the fourth toe are slightly notched. The head is of medium size, the forelimbs are short, and the hindlimbs are of medium length. The tibia is also medium in size. The dorsal skin is extremely folded, with a network of wrinkles running in all directions, but it has few warts. The wrinkles are very faint on the eyelids, and the top of the snout is almost smooth. The dorsal side of the tibia is scattered with small, low warts that have white tips. The tip of the fourth toe is swollen into a large disk that is wider than the basal phalanx and significantly wider than the disk on the third finger. The fourth toe is broadly webbed all the way to the disk. The dorsum is dark brown and lacks any darker markings.

The natural history of the species is mostly unknown.