Nobody can say for sure why these animals are missing a finger
Back in 2007, biologist Michel Garey stumbled upon a three-fingered frog while investigating the biodiversity of southern Brazil's rainforests. However, these three-fingered frogs had to wait until 2012 to be officially listed as a new species.This is because Michel Garey first had to conduct various studies and make sure these animals were indeed significantly different from others of their kind.
Apparently, the fact that these frogs only have three fingers is a direct result of their evolving and adapting to their natural habitats, and has nothing to do with issues such as soil and water pollution.
“I was doing research with two friends on a hilltop in the reserve and I stumbled into this unusual frog with only three fingers. It happened on February 14, 2007: My birthday. What a treat!” Michel Garey commented with respect to his findings.