Scientists have discovered six new species of frog the size of a thumbnail (拇指甲) in the forests of Mexico, with one earning the distinction of Mexico's smallest frog.
All six species are(small) than an Australian five-cent coin around 15 mm long when they are fully(grow). Adult males of the tiniest of these species, named Craugastor candelariensis, growonly 13 mm. The newly discovered species(know) as "direct-developing" frogs: Rather than hatching from eggs into tadpoles (蝌蚪)like most frogs. they emerge from the eggs as perfect mini frogs. And they're so small that they're right atbottom of the forest food chain.
With millions of these frogs(live) in the leaf litter, they're likely to play a(huge) important role in the ecosystem as a source of food for everything else, from lizards to predatory birds. Until now these new species(go) unnoticed because they're small and brown and look really similar to other frogs.
Their lifestyle is completely fascinating. These frogs live in the dark, humid leaf litter of the forests,is like a secret world. Scientists don't really know anything about what goes on there. They don't understand their(behave), how they socialize or how they breed.
