The family Caenolestidae, commonly known as shrew opossums, is a small group of marsupials native to the Andean regions of South America, particularly in Chile, Argentina, and Peru. These animals are small, nocturnal, and insectivorous, with elongated snouts and slender bodies adapted for hunting in leaf litter and undergrowth. Unlike many other marsupials, they have a reduced or absent pouch, and their young cling to the mother’s teats during early development. Shrew opossums are considered relict species, representing an ancient lineage of South American marsupials that has survived since the continent’s isolation. They are generally solitary and elusive, making them poorly understood, but they play an important ecological role as insect predators in their mountainous habitats.