Pygmy hippopotamus unusual secretion as common hippos, that gives a pinkish tinge to their bodies, and is sometimes described as "blood sweat" though the secretion is neither sweat nor blood. This substance, hipposudoric acid, is believed to have antiseptic and sunscreening properties. The skin of hippos dries out quickly and cracks, which is why both species spend so much time in water. The skeleton of "C. liberiensis" is more gracile than that of the common hippopotamus, meaning their bones are proportionally thinner. The common hippo's spine is parallel with the ground; the pygmy hippo's back slopes forward, a likely adaptation to pass
Mountain pygmy possum is hairless. On the underside of the female's body is a pouch containing four teats. This possum is the only extant species in the genus "Burramys". It is also the only Australian mammal restricted to alpine habitat. The mountain pygmy possum was first discovered in the fossil record in 1895 when a portion of the jaw and skull bones were found in the Wombeyan Caves in central New South Wales. At the time, the species was believed to be extinct. It was not until 1966 that a living individual was found at a ski resort at Mount Hotham in Victoria.