Biology Fun Facts

About Short-Tailed Opossums (STO)

short-tail opossum poking his nose into bark

Short tail opossums are small: They are close in size to a large gerbil or hamster.
Short tail opossums are pouchless marsupials: Unlike kangaroos and koalas, STO do not have a pouch. Sure, "pouchless marsupial" sounds strange, but so does "flightless bird" (penguins) and "jumbo shrimp"!
Short tail opossums are South American marsupials: Opossums from South America are the only marsupials surviving to modern times outside of Australia.
Short tail opossums have opposable toes: The "big toe" on their hind feet are opposable like our thumbs.
Short tail opossums have suction cup-like feet: STO can sometimes climb up smooth surfaces like glass because of the pads on their feet and opposable toes.
Short tail opossums have 2 toenails and 8 claws: Opossums and primates are the only mammals with nails - other mammals have only claws.
Short tail opossums have a prehensile tail: Their prehensile tail is used as a fifth limb and they even carry light objects with it.
Short tail opossums have a very short gestation period: At only 2 weeks, their gestational period is one of the shortest for any mammal.
Short tail opossums are born very undeveloped: Newborn baby STO are only as developed as a 6-week old human fetus.
Short tail opossums can develop skin cancer: STO, like humans, are one of the only mammals that develop skin cancer from sunlight alone - other animals need combinations of sunlight, genes and chemical carcinogens.