Seven miniature frog species have been discovered high in the Atlantic Forest of Brazil. Each of these previously unknown varieties of animals measures less than a half-inch in length.

The newly discovered frogs are all members of the genus Brachycephalus, a variety of animals first described by biologists in the 19th century. All of the seven species are adorned in bright colors, which likely evolved as a means of warning would-be predators of neurotoxin in the skin of the frogs.

The frogs were found following an extensive five-year search for unknown species of Brachycephalus in the Brazilian Atlantic Rainforest. These animals are among the smallest of all vertebrates living on land.

Brachycephalus leopardus has yellow skin with dark spots, which inspired the species' feline name. These tiny amphibians piggyback, with a male on top of a female, during mating, and he fertilizes eggs the female lays in water.

Another of the species with a descriptive name is Brachycephalus olivaceus, with greenish-brown skin.

"Researchers collected an adult female of this species at the base of the Serra Queimada mountain in Santa Catarina's municipality of Joinville, on Jan. 23, 2011," Jeanna Bryner wrote for Live Science.

Brachycephalus verrucosus has dark orange skin, covered by lumpy greenish-brown spots. A dark green, uneven stripe runs down the back of Brachycephalus fuscolineatus, setting the area off from the rest of the body, which is mostly yellow. A similar stripe, in light blue hues, adorns the backbone of Brachycephalus mariaeterezae. Just the opposite of these is Brachycephalus boticario, featuring green on the flanks and an orange spine.

The isolated cloud forest environment, high on top of mountains, provides these amphibians with an ideal climate. However, the habitat is also vulnerable to climate change, as well as human encroachment and deforestation. Each of the species lives on just one or two mountaintops in the region, and biologists believe the animals are unable to move to other summits.

"Although getting to many of the field sites is exhausting, there was always the feeling of anticipation and curiosity about what new species could look like," Marcio Pie from the Universidade Federal do Paraná in Brazil said.

Naturalist Johann Baptist von Spix discovered the first member of Brachycephalus in 1842, but most species of the genus were first described in the last decade, due to their remote habitat.

Cloud forests are highly susceptible to the effects of environmental changes, which could result in damage to frog populations in the future.

Discovery of the seven new species of miniature frogs was published in the journal PeerJ, a peer-reviewed open access journal.