The family Microbiotheriidae is a small group of marsupials native to South America, with its only extant species being the monito del monte (Dromiciops gliroides). These animals are small, nocturnal, and arboreal, primarily inhabiting temperate forests of Chile and Argentina. Microbiotheriids are considered living fossils, as they represent the only surviving members of an ancient lineage closely related to Australian marsupials, reflecting the historical biogeographical connection between South America and Australia. They feed mainly on insects and fruit, play a key role in seed dispersal, and have a low reproductive rate, typically giving birth to a few underdeveloped young that continue development in the mother’s pouch. Their conservation is important due to habitat loss and their ecological role in forest ecosystems.