Barbourula kalimantanensis is the sole representative of the family Bombinatoridae on the island of Borneo. The species was described first in 1978 by Iskandar, and until recently was known from only two specimens. A second species, B. busuangensis, is known from the Palawan group of islands of the Philippines.

Barbourula kalimantanensis is strange-looking: it belongs to an archaic family of frogs with many primitive character states in their anatomy, but on the other hand, shows extensive adaptations for an aquatic mode of life in streams. The species is nocturnal. During the day these frogs will hide under rocks and boulders and will be nearly impossible to detect. For this and the restricted distribution range it is not surprising, that only very limited information about its biology has been collected by scientists. 

The reproductive mode and most aspects of its ecology and physiology remain unknown. However, details of the reproductive mode in B. busuangensis have been published (more on that here) and there is a high likelihood that B. kalimantanensis shares the same reproductive mode (unless proven otherwise). 

Size of adults: approx. 70 mm

The rare images of living specimens on this web page were kindly provided by Dr. Tan Heok Hui (Raffles Museum of Biodiversity Research, Singapore) and Lars Fehlandt.