The text states that the smallest mammal is the pygmy bamboo lemur, weighing about 30 grams, and that these lemurs inhabit Madagascar, contributing to its unique ecosystem.

The claim that the pygmy bamboo lemur is the world's smallest mammal is incorrect based on the evidence. The pygmy shrew is consistently cited as the smallest mammal, weighing as little as 2 grams. No evidence directly supports the claim about the pygmy bamboo lemur's size being the smallest. The pygmy bamboo lemur does inhabit Madagascar, contributing to its unique ecosystem, but this claim was not under verification. Conclusions are based on findings that refute the first claim with reliable source data.