Long considered loners, many marsupials may have complex social lives
Previous assumptions about the earliest mammals likely being solitary may also need revisiting
Many marsupials, such as the squirrel glider (Petaurus norfolcensis) shown here, can live in a variety of social groups, such as a mating pair or a bigger group of males and females, according to a new study.
Sylvain Cordier/Stockbyte/Getty