The Colugo: Gliding
There were probably many mammalian attempts at flying before the success of the highly specialized bats. In Malaysia and the Philippines there lives an odd animal called the colugo or flying lemur (Cynocephalus volans) and has been classified in its own order Dermoptera. It is about the size of a large rabbit but its entire body, from its neck to the end of its tail, is covered by a softly furred cloak of skin. When the animal hangs beneath a branch or presses itself against a tree trunk, its camouflaged patterning on its fur makes it almost invisible, but when it extends its legs, the cloak becomes a gliding membrane. The colugo's gliding technique has several parallels. The marsupialsugar glider planes through the air in just the same way. Two groups of squirrels have also independently acquired the talent. But the colugo has the biggest and most completely enveloping membrane and took to the habit early in mammalian history, for it is certainly a very primitive member of the group and seems to be a direct descendant of an insectivore ancestor. A few Palaeocene and Eocenefossils from North America are very similar to the living Colugo and therefore it is considered to be a fairly primitive animal. Having perfected a gliding life style, the Colugo has remained unchallenged and unchanged. Colugos cannot be regarded as a link with the bats, for its anatomy is entirely different in many fundamental aspects, but it is an indication of a stage that some early insectivores may have passed through on their way to achieving flapping flight that occurs in bats which are classified in the order Chiroptera.