Seven new teeny-tiny frog species have recently been discovered in the cloud forests of Brazil, and though they were just found, scientists already say that they are threatened and on the brink of extinction.

The southern Brazilian Atlantic Rainforest harbors a highly unique group of frogs that have intrigued scientists for over a century. Known as Brachycephalus, these miniature frogs are among the smallest terrestrial vertebrates, with adult sizes often not exceeding 1 cm in length. Their pocket size yields unique changes to their body structure as well, including a reduced number of toes and fingers.

And though the brightly colored amphibians look adorable, don't let them fool you. They are extremely poisonous. They likely use their vibrant colors to ward of predators from the highly potent neurotoxin in their skin known as tetrodotoxin.

Most species of Brachycephalus are highly endemic, meaning they are found exclusively on one, or a few, adjacent mountaintops. That's because over time they have learned to adapt to a very specific kind of habitat, though that simultaneously prevents them from migrating across valleys and promotes the formation of new species. It also makes them highly vulnerable to extinction, particularly due to shifts in the distribution of cloud forest due to climate change.

Cloud forests are highly sensitive to climatic changes, and the long-term preservation of these species might involve not only the protection of their habitats but also more direct management efforts, such as rearing in captivity.

The first species of Brachycephalus was described in 1842 by the famous German naturalist Johann Baptist von Spix, yet most species in the genus have been discovered only in the past decade. Their endemic nature and remote habitat makes them difficult to find. But after nearly five years of exploration in these mountainous areas, a team of researchers has managed to discover seven new species on seven mountaintops - providing the largest addition to the known diversity of Brachycephalus.

"This is only the beginning, especially given the fact that we have already found additional species that we are in the process of formally describing," researcher Luiz Ribeiro, from the Mater Natura Institute for Environmental Studies, said in a press release.

And now that more of these miniature frogs have been discovered, perhaps scientists may now work to better protect these rare and threatened species.

The findings were published in the journal PeerJ.

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