[2] A molecular phylogenetic study by van der Meijden, et al. (2007) has estimated the initial internal divergence of the family Microhylidae to have taken place about 66 million years ago, or immediately after the Cretaceous extinction event.

[1] The most recent common ancestor of the Microhylidae and their closest ranoid relatives is estimated to have lived 116 million years ago in Gondwana.

The two main shapes for the microhylids are wide bodies and narrow mouths and normal frog proportions.

The microhylids of New Guinea and Australia completely bypass the tadpole stage, with direct development from egg to frog.

The tadpole lacks keratinized mouth parts and has a large spiracular chamber emptied by a caudomedial spiracle.