The Musculature and limb plexuses of Trichosurus vulpecula.

Abstract

A full account is presented of the anatomy of the skeletal musculature of the marsupial Trichosurus vulpecula, its innervation is noted, and an outline of the brachial and lumbo-sacral plexuses is given, the findings reported being the results of a study involving five separate animals. All discrepancies between the findings of this investigation and those previously reported for the species are noted, a comparison is made with the muscles described for other marsupials, and the relatively few unusual features shown by this species are pointed out. From this comparison it is concluded that the musculature shows a fairly generalized pattern and bears a closer resemblance, both in its overall structure and in the few uncommon features that it presents, to the cuscuses than to any other marsupials that have been adequately described. The cuscuses, which have been described in the literature quoted in this paper under the generic names Phalangista, Cuscus, and Phalanger are the only other members of the Phalangerinae for which adequate accounts of the muscular system are available. This work, apart from providing the most comprehensive description yet given of the musculature of any single marsupial species, furnishes additional evidence for the view that the vulpine phalanger is a typical phalangerine of a basic generalized marsupial structure such as probably characterized the original phalangeroid stock.