FUNCTIONAL-ANATOMY OF GLIDING MEMBRANE MUSCLES IN THE SUGAR GLIDER (PETAURUS BREVICEPS)

In order to clarify the morphological adaptation for gliding behavior in the marsupial mammals, the gliding membrane muscles in the sugar gl ider (Petaurus breviceps) were observed. Unlike the styliform cartilag e in flying squirrels, the sugar glider has a well-developed tibiocarp alis muscle in the most lateral area of the gliding membrane. The glid ing membrane substantially consists of the humerodorsalis and tibioabd ominalis muscle complex. We believe that the thick tibiocarpalis bundl e and the humerodorsalis and tibioabdominalis muscle complex may serve as a membrane controller in the gliding behavior. A characteristic th in membranous structure between the cutaneous and deeper muscles was o bserved. In addition to the direct powerful control exerted by trunk a nd limb movement, we suggest that indirect power conduction by this th in membranous structure may contribute to gliding membrane control.