Currently, the family includes four genera,
Eodelphis,
Didelphodon,
Fumodelphodon and
Hoodootherium, which together include some seven different species. if confirmed it would make it the only known
Cenozoic and the only known
South American member of the family. Stagodontids were some of the largest known Cretaceous mammals, ranging from in mass. One of the most unusual features of stagodontids are their robust, bulbous premolars, which are thought to have been used to crush
freshwater mollusks, a diet that apparently evolved independently at least twice within this clade. Postcranial remains suggest that stagodontids may have been semi-aquatic. The most well described forms are found in
Laramidia, but they are also present on
Appalachian and
South American sites, further leading credence to their aquatic habits. Cretaceous fossils were also found in
France, suggesting a pan-Laurasian distribution for Cretaceous metatherians. They are considered rare in any given fauna they appear in, probably due to their specialised habits. ==Classification==