New Species of Tiny, Poisonous Frog With Glowing Bones Discovered in Brazil

Meet the newest member of the amphibian family: a deceptively cute, bright-orange toadlet small enough to fit on a fingernail.

The new species is a type of "pumpkin toadlet," of the genus Brachycephalus, says These types of frogs, which are native to the forests of Brazil's southeast coast, feature intense tangerine coloring and measure less than two centimeters in length. As adorable as they may be, they pack a mighty punch for something of their size. According to New Scientist, the creatures' skin "secretes a powerful neurotoxin."

The new species, Brachycephalus rotenbergae, is distinct from its fellow pumpkin toadlets in that it is slightly smaller, has black spots, and has about 3% of different DNA. New Scientist reported that these distinctions warranted the classification of a new species.

Brachycephalus rotenbergae
Images from Nunes' study on the new species of 'pumpkin toadlets.' Ivan Nunes et al./PLOS One

However, like its peers, Brachycephalus rotenbergae has fluorescent plates of bone on its skull and back. The plates glow through the frogs' skin when exposed to UV light. Researchers aren't yet sure of the glowing bones' function, but they suspect they might play a role in communication.

Ivan Nunes, who led the research on Brachycephalus rotenbergae and whose findings were published in PLOS One last week, notes that the frogs' vibrant orange color "may also work as a camouflage in their microhabitat, since there are great amounts of tiny yellow and orange leaves, mushrooms and seeds on the ground...especially during the active season."

The creatures live primarily "in the forest leaf litter and are most active during daylight," meaning that despite their attention-grabbing appearance, they are able to blend in seamlessly with their environment.

"During our field surveys," Nunes wrote, "it was quite common to mistake a specimen for other yellow/orange small things on the landscape."

Orange, fluorescent & the size of a thumbnail; the newly discovered amphibian Brachycephalus rotenbergae, a type of pumpkin toadlet found in Brazil’s Atlantic Forest. The thumbnail-size amphibian lives in Brazil’s Atlantic Forest, which has lost 93% of its forest cover.

— DAILY BUGLE (@Dailybugle1898) May 1, 2021

Nunes and his colleagues at São Paulo State University conducted the study by gathering 276 toadlets, says New Scientist. After studying their physical characteristics, they noticed that a group of frogs in the southern Mantiqueira mountains were unique—these were the toadlets later classified by researchers as Brachycephalus rotenbergae.

According to researchers, adult male Brachycephalus rotenbergae measure between 1.35 and 1.6 cm long and females are between 1.6 and 1.8 cm.

As New Scientist pointed out, there is still much unknown about the Brachycephalus rotenbergae species. Specifically, little is known about their reproductive and feeding habits. And, while the population of tiny amphibians is currently well-protected, Nunes noted the creatures display a " environmental disturbances" like habitat loss.