Didelphidae

Didelphidae, commonly known as opossums, is the largest family of marsupials in the Americas, containing more than 100 species in roughly a dozen to twenty genera. The best-known member is the North American Virginia opossum (Didelphis virginiana), found across much of the United States and parts of southern Canada, with related species occupying Central and South America. Other genera include Marmosa, Monodelphis, Caluromys, Philander, Gracilinanus, and Thylamys.

Didelphids show a broad range of sizes and lifestyles, from arboreal to terrestrial. They are generally nocturnal omnivores, feeding on insects, fruit, small vertebrates, carrion, and eggs. A common feature in many species is a relatively long tail, which is often used for balance and, in some species, grasping branches. They tend to be adaptable and are found in forests, grasslands, wetlands, and increasingly in urban areas.

Reproduction is characteristic of marsupials: young are born highly undeveloped and complete their development by nursing on the mother’s teat(s) in a pouch or within fur attachments. Many species can produce multiple litters per year, depending on climate and resource availability.

Taxonomically, Didelphidae is divided into several genera, including Didelphis, Philander, Marmosa, Monodelphis, Caluromys, Gracilinanus, and Thylamys. The group has a long fossil history in the Americas, reflecting an ancient lineage among marsupials in the Western Hemisphere. Conservation status varies among species, with some common and widespread and others threatened by habitat loss and other pressures.