Three new species of tiny frogs were discovered in Papua New Guinea by researchers from the University of Michigan.

Researcher Dr Fred Kraus from the University of Michigan was instrumental in adding three new species of tiny frogs from the genus Oreophryne after discovering them in Papua New Guinea.

The three new species have been named Oreophryne cameroni, Oreophryneparkopanorum and Oreophryne gagneorumare. They have small bodies, measuring up to 20 mm in length but are substantially larger than the tiniest frog species. In 2011, Kraus wrote a detailed description of the world's smallest frog species - Paedophryne dekot and Paedophryne verrucosa in the journal ZooKeys.

According to Kraus, the smallest two species, 8 to 9 mm in size,  are half the size of the three newly discovered frog species.

Kraus and his team of researchers also noted that the new species are largely restricted to New Guinea and satellite islands. At this time, this genus appears to be the largest in the Papuan region.

"Although the description of the new species treated herein now brings to seven the number of Oreophryne species reported from the north-coast region of New Guinea, the presence from these areas of additional specimens of uncertain identity suggests that additional species likely await description," said Dr Kraus about the diversity of the genus within the region in a press release. "I have at least a dozen more new Oreophryne species remaining to be described from this region, and large portions of this terrane system remain unsurveyed."

Findings of the new discovery have been described in the latest issue of Zookeys.