[5] Widely distributed east of the Andes: originally discovered in Brazil,[2] reported to exist in Argentina, Bolivia, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, and Venezuela.

This practice and morphological similarities are shared with its African relative Boulengerula taitana, suggesting it evolved over 100 million years ago.

[7] As detailed in a 2024 study, researchers collected 16 mothers of the species from cacao plantations in Brazil's Atlantic Forest and filmed them with their altricial hatchlings in the lab.

This milk-like substance, rich in fats and carbohydrates, is produced in the mother's oviduct epithelium’s hypertrophied glands, similar to mammal milk.

The researchers observed the hatchlings emitting high-pitched clicking sounds as they approached their mothers for milk, a behavior unique among amphibians.

The presence of milk production in caecilians that lay eggs suggests an evolutionary transition between egg-laying and live birth.