There are 41 species in this family.

Saddleback toads are found in the forests of southeastern Brazil and northern Argentina. They are tiny and have three digits on each hind leg and two on their front legs. Most frogs and toads have five digits on their hind legs and four digits on their front legs.

Saddleback toads are also known as shield toads because of the bony shield above their vertebrae. They are also known as pumpkin toads because of their orange color.

Saddleback toads live in the leaf litter on the forest floor. Because they lay their eggs on the ground, they do not have a tadpole stage of development.

One species in this family, the flea frog, Rachycephalus didactylus, is the smallest frog in the Southern Hemisphere. It is bright gold and only a little larger than 3/8 of an inch in length. It is also known as the Brazilian gold frog and the Brazilian flea frog.