Chiasmocleis

Chiasmocleis is a genus of frogs in the family Microhylidae. They live in tropical South America north and east of the Andes. English speakers call them humming frogs or silent frogs.
Taxonomy.
Scientists have trouble deciding where to put this genus because it looks like not all of these frogs have the same ancestor. As of mid 2021, scientists agreed to put frogs that used to be in the genus "Syncope" into "Chiasmocleis", but they also agreed to make three clades into subgenera:
Of these, "Relictocleis" is the most different from the other two. Some scientists think it should be its own genus. "Relictocleis gnoma" would be its only species.
Description.
"Chiasmocleis" frogs have small bodies and small legs. The male and female frogs look different: Male frogs have darker chins, and some of them have spines. The frogs from the subgenus "Syncope" are even smaller and have fewer bones in their paws and tose. "Relictocleis" frogs are also very small.
Ecology.
"Chiasmocleis" live underground some or most of the time. They are hard to see against dirt or dead leaves. They only look for food on the surface for a few days during the time when they lay eggs. This is at the beginning of the rainy season. They live in both forests and open places.
Species.
These species are in "Chiasmocleis":