Forked for Her Pleasure
Male opossums have a bifurcated (forked) penis to match the female's two-branched reproductive tract.
North America's only marsupial, the opossum, has reproductive anatomy as unusual as its lifestyle. Males have a bifurcated (forked) penis that splits into two branches at the tip.
This peculiar shape evolved to match the female's anatomy. Like kangaroos and other marsupials, female opossums have two lateral vaginas. The forked penis allows the male to deposit sperm in both branches simultaneously.
Early European settlers in America were puzzled by opossum reproduction. Observing the male's forked penis and not understanding its purpose, they developed an incorrect theory that opossums mated through the nose, and that the female then sneezed the babies into her pouch. This myth persisted for centuries.
The reality is more conventional (if still unusual by mammal standards). After mating, fertilized eggs travel to the two uteruses. Baby opossums are born after only 12-13 days — one of the shortest pregnancies of any mammal. The newborns, about the size of honeybees, must crawl to the pouch and attach to a nipple.
A female opossum can have up to 13 nipples, but typically only the strongest babies survive — those that make it to the pouch and secure a nipple.