New diamond frog species found in northern Madagascar

June 16 (UPI) -- Scientists have discovered a new species of diamond frog in the dense tropical forests of northern Madagascar. The new species, Rhombophryne ellae, belongs to a genus that has doubled in diversity over last decade.

The diamond frog was found inside northern Madagascar's Montagne d'Ambre National Park, which is known for its rich biodiversity.

While the national park's flora and fauna are relatively well-studied, its forests continue to offer up previously undescribed species.

In recent years, the park's reptile and amphibian populations have offered scientists a wealth of surprises. Rhombophryne ellae -- described Tuesday in the journal Zoosystematics and Evolution -- is only the latest.

"As soon as I saw this frog, I knew it was a new species," lead researcher Mark D. Scherz said in a news release. "The orange flash-markings on the legs and the large black spots on the hip made it immediately obvious to me.

"During my master's and Ph.D. research, I studied this genus and described several species," said Scherz, herpetologist with the Bavarian State Collection of Zoology in Germany. "There are no described species with such orange legs, and only few species have these black markings on the hip."

Often, new species look so similar to their relatives that scientists must resort to DNA analysis to confirm two species are genetically -- and taxonomically -- distinct. The new diamond frog species is so visibly distinct, scientists didn't need to wait for the genomic sequencing results -- they knew.

The newly named frog's closest relative is an undescribed frog from Tsaratanana, an area 300 miles south of Montagne d'Ambre National Park.

Though the new species is quite different from most other diamond frogs, he is one of many hopping amphibians to boast red to orange flash-markings. Although the color pattern has evolved dozens of times in frogs, scientists still aren't sure of its function.

Now that Rhombophryne ellae is official in the scientific literature, Scherz and his colleagues will turn their attention to the frog's unnamed relatives. In Madagascar, the work of biological discovery is never-ending.

"The discovery of such a distinctive species within a comparatively well-studied park points towards the gaps in our knowledge of the amphibians of the tropics," Scherz said.

"It also highlights the role that bad weather, especially cyclones, can play in bringing otherwise hidden frogs out of hiding -- Rhombophryne ellae was caught just as Cyclone Ava was moving in on Madagascar, and several other species my colleagues and I have recently described were also caught under similar cyclonic conditions," he said.