Newly-Discovered Brazilian Toad is Among World's Tiniest

Thought Question: If you could discover a new tiny animal, what would it be like and what special abilities would it have?

How small is Brachycephalus dacnis, the newly-discovered species of toad that calls Brazil’s Atlantic forests home? The ants that most toads call dinner would be more likely to make a meal out of the tiny amphibian.

“We are talking about the limits of life size on Earth,” Luís Felipe Toledo, a herpetologist at the University of Campinas, told The New York Times (NYT).

Toledo’s team didn't find the “flea toadlet” by sight. It camouflages its 6.95-millimeter-long body well! Rather, they found the toadlet by sound. Their mating calls sound like crickets chirping. The team used it to track the wee creature, which can leap up to 30 times its own body length.

B. dacnis jumps like other toads. But it only has two fingers on each hand. Most toads have 4 fingers per hand. And B. dacnis only has three toes on each foot. Much like humans, your backyard garden toad has 5. B. dacnis also lays eggs that hatch directly into adult form. That means there's no tadpoles for this toadlet.

The new species joins its Brachycephalus cousins as one of the smallest vertebrates on the planet. Other tiny spine-havers include the New Guinea Amau frog, which averages 7 millimeters in length, and the dwarf goby fish (7.9 millimeters). And because it’s so small, scientists believe there may be more mini species to discover yet. 

“There are untold numbers of unknown tiny frogs out there,” Mark Scherz, curator of herpetology at the Natural History Museum of Denmark, told the NYT. “These small species have been overlooked (before), by virtue of how hard they can be to find and collect.”

Image courtesy Toledo LF, Botelho LM, Carrasco-Medina AS, Gray JA, Ernetti JR, Gama JM, Lyra ML, Blackburn DC, Nunes I, Muscat E. 2024. “Among the world’s smallest vertebrates: a new miniaturized flea-toad (Brachycephalidae) from the Atlantic rainforest,” published in PeerJ.