The Comparative Myology of the Gliding Membranes of Acrobates, Petauroides and Petaurus Contrasted With the Cutaneous Myology of Hemibelideus and Pseudocheirus (Marsupialia, Phalangeridae) and With Selected Gliding Rodentia (Sciuridae and Anamoluridae)

Abstract

The comparative myology of the gliding membranes of the marsupial genera Acrobates, Petauroides, Petaurus and Hemibelideus is compared with that of the skin musculature of the non-glider Pseudocheirus. An outline of the system used in the naming of the parts of the cutaneus maximus is included. The gliding membranes are compared, functionally, with those of the rodent Petauristinae; the positions of the muscles within the phalanger membranes account for the gliders' ability to execute changes in camber, thus lift and angle of attack. An accessory cartilage associated with the elbow of Petauroides helps to increase the size of the plagiopatagium; its anatomy is compared with that of a similar cartilage in the rodent genus Anomalurus. A scheme for the evolution of the gliders' dermal musculature from a Pseudocheirus- type ancestor is presented; it is suggested, because of its anatomy and habits, that Hemibelideus be elevated to full generic status.