Marsupials and placental mammals: A resemblance
Sometimes the resemblance between placental and marsupial forms is so close that you need to examine the animals closely in order to distinguish them. The sugar glidersPetaurus spp. are small leaf and blossom eating marsupials that live in eucalyptus trees. They have a parachute of skin connecting its fore and hind legs which enable them to glide from branch to branch and resemble almost exactly the North Americanflying squirrel (Petaurista alborufus). The similarity is based on similar lifestyles requiring similar forms. For example in order to have lifestyle that relies on gliding you will need to have structures that function as parachutes. A burrowing lifestyle also demands particular structures that are similar for marsupial and placental animals alike. Placentalmoles (e.g. Cape Golden MoleChrysochloris asiatica) and marsupialmoles (Notoryctes) both have short silky fur, reduced eyes, powerful digging forelegs and a stumpy tail. The distinguishing feature is that the female marsupial mole possesses a pouch, which unlike other marsupials opens from the rear and therefore does not fill with earth when she burrows.