Kubah Narrow-Mouthed Frog

Microhyla borneensis (junior synonym Microhyla nepenthicola), also known as the Matang/Kubah narrow-mouthed frog, is a species of microhylid frog found in the Matang Range in Sarawak, Borneo. It was once the smallest known frog from the Old World (the current record holder is Paedophryne amauensis from New Guinea). Adult males of this species have a snout-vent length (SVL) of 10.6–12.8 mm (0.42–0.50 in) and Females of up to 19 mm. Tadpoles measure just 3 mm.

Microhyla borneensis was first described by Hampton Wildman Parker in 1928. Frogs of the species that was eventually described as Microhyla nepenthicola had been known for at least 100 years prior to its description in 2010. However, scientists had always assumed that the frogs were juveniles of another species. Researchers Indraneil Das and Alexander Haas recognized that they were actually adults when they heard the frogs calling in Kubah National Park, since only adult frogs make calls. Adult males call from the pitcher plants at dusk. However, in 2011 it was shown that Microhyla borneensis and Microhyla nepenthicola are the same species. What was until that point commonly known as Microhyla borneensis was another species, newly described as Microhyla matang.