Researchers have discovered the world's second-smallest vertebrate in the Atlantic Rainforest of Brazil.
This tiny creature, a flea toad, is so small it can fit on the tip of your finger. Interestingly, it looks smaller than some of the known ant species.
A team of scientists from the State University of Campinas in Brazil has recently discovered this new species, named Brachycephalus dacnis.
This flea tod measures just 6.95 millimeters in length. A separate research team had earlier identified another species within the same genus, B. pulex, in the southern Bahia state of Brazil. One of the individuals measured a mere 6.45 mm in length.
Miniature size
This marks the seventh species of flea toad to be described within the genus Brachycephalus. The toad's small size is an adaptation to its unique environment.
Flea toads are tiny adults, measuring less than 1 cm. These toads are so tiny that their adult size is significantly smaller than a typical human fingernail or a 50-cent coin.
“There are small toads with all the characteristics of large toads except for their size. This genus is different. During its evolution, it underwent what we biologists call miniaturization, which involves loss, reduction and/or fusion of bones, as well as fewer digits and absence of other parts of their anatomy,” said Luís Felipe Toledo, corresponding author and professor in the Institute of Biology (IB-UNICAMP).
Typically, this genus of toads is primarily known for its vibrant coloration and venomous nature, particularly species like the pumpkin toadlets. However, recent discoveries, including the newly described B. Dennis, have shifted researchers' attention toward the extreme miniaturization exhibited by certain species within this genus.
Earlier studies have pointed out that pumpkin toadlets possess fewer anatomical structures than flea toads despite their larger size. This includes the absence of a tympanic middle ear, which results in their inability to perceive their own vocalizations.
https://www.youtube.com/watch?v=aTuBp-TBWz8
DNA analysis confirmed new species
The unique vocalizations of the newly described species, B. dacnis, captivated the researchers' attention.
The diminutive toad, with its yellowish-brown skin, resides within leaf litter.
Despite their size, flea toads are incredibly complex creatures. It exhibits direct development, bypassing the tadpole stage and hatching as fully formed miniature versions of itself.
DNA analysis verified that B. dacnis is a new species in the genus. It is closely related to another yellow-brown skin toad of the same genus B. hermogenesi.
“There may have been specimens belonging to the new species among those that served as a basis for describing B. hermogenesi in 1998,” Toledo said.
The researchers described the new species, including its anatomy, skeletal structure, internal organs, genetics, and vocalizations.
“The diversity of these miniature frogs may be far greater than we think. Hence the importance of describing as many traits and features as possible, to expedite the description process and get to work on conservation as quickly as possible,” Toledo said in the press release.