Background: Flight is the central avian adaptation in evolution. Wing muscles form an important anatomical basis for avian flight, affecting wing performance and determine modes of flight. However, the roles of distal muscles in adjusting the wing, as well as their functional specializations, remain largely unknown. The importance of muscle fiber architecture has long been recognized. In this study, we provide quantitative anatomical data on the muscle architecture of the forelimb of the Golden Pheasant (Chrysolophus pictus), with an emphasis on brachial, antebrachial and manual segments. Methods: The forelimbs of five Golden Pheasants were dissected and detailed measurements of all muscles were made, including muscle mass, muscle belly length, fascicle length. From these values, muscle volume, physiological cross-sectional area (PCSA) and maximum isometric force were derived.

SUMMARY:Morphological work on the appendicular myology of birds forms the basis for comparative, functional and systematic studies, but our knowledge of the descriptive anatomy of birds is still very incomplete. The musculature of the wing muscles of the Golden Pheasant (Chrysolophus pictus), an endemic species of China, is studied in detail. All wing muscles are present as in other Galliformes. Myological characteristics including the absence of a deep layer of M. pectoralis pars thoracicus, well development of anterbrachial muscles, as well as the occurrence of a distinct fleshy slip from the proximal belly of M. biceps brachii, are suggested to be associated with its flapping flight. This paper is the prelude to functional analysis on muscle architecture in this species and may serve as a basis for future taxonomic comparisons.