DNA Reveals Hidden Species Among Borneo’s “Fanged Frogs”

Some of the most important discoveries in biology happen not in a rainforest but in a test tube. That was the case for a group of small brown frogs from Southeast Asia known as Bornean fanged frogs, named for the tooth-like projections in their lower jaws. Scientists have long puzzled over how many species the group really contains, and a study reported on March 9, 2026, used genetics to bring the picture into focus.

A team led by herpetologist Chan Kin Onn at Michigan State University examined more than 13,000 genes across frogs collected from the mountainous rainforests of Malaysian Borneo. Earlier work had suggested the group might hide as many as 18 species; the new genomic analysis points instead to about six or seven truly distinct species. As the researchers put it, it is “not just one species, but it’s not 18 species, either.” The findings were published in the journal Systematic Biology.

“That was the case for a group of small brown frogs from Southeast Asia known as Bornean fanged frogs, named for the tooth-like projections in their lower jaws.”

The result is a lesson in the messy reality of how species form. Rather than splitting cleanly into separate lineages, these frogs showed significant interbreeding between populations, evidence that, as the team noted, the birth of a new species is rarely an abrupt event but unfolds along a continuum with blurred boundaries. Untangling that blur takes the kind of careful, gene-by-gene detective work this study exemplifies.

Getting the count right is more than an academic nicety. Amphibians are among the most threatened animals on Earth, and accurate species identification is essential for protecting them, while overstating the number of species can scatter scarce conservation resources too thinly. By drawing a clearer map of this frog family tree, the researchers have given conservationists better tools to safeguard Borneo’s remarkable amphibians, a quiet but meaningful win for biodiversity.