Gross anatomical study on bones of pectoral girdle in black swan (Cygnus atratus)

Abstract

The pectoral girdle of black swan consists of scapula, clavicle and coracoid. The scapula was a sword shaped bone positioned lateral and parallel to the vertebral column and extended caudally to the pelvis. The cranial extremity consisted of lateral articular facet for articulation with the head of the humerus and a medial rounded process. The scapula joined with the clavicle craniomedially. Foramen triosseum was formed with clavicle and coracoid for the head of humerus. The clavicle was in the form of a sickle shaped bone. A pair of clavicles fused ventrally to form broad ‘U’ shaped furcula. The hypocleidium was absent. The coracoid was a thick rod-shaped and strongest bone of the pectoral girdle. The cranial extremity was characterized by the presence of humeral, scapular, and acrocoracoid tuberosities, acromial process and supracoracoid groove. The caudal extremity was quadrilateral and consisted of spatula shaped concave elongated facet for articulation with sternum.