Gross Morphological Studies on Sternum and Shoulder Girdle of Red Wattled Lapwing (Vanellusindicus)

Abstract

The present study was conducted on the sternum and shoulder girdle of red wattled lap-wing. Bones were collected by maceration technique. The sternum was boat shaped in outline. Dorsal surface presented a longitudinal median groove and smooth due to pneumatic foramen. However, a triangular depression and two foramina/fenestrae were observed at the cranial and caudal ends of dorsal surface, respectively. A well-developed sternal crest projected from ventral surface. Caudolateral processes enclosed a lateral notch on either side of lateral border.Cranial border of sternum displayed a transverse groove enclosed by a dorsal and a ventral ridge.The dorsal ridge consisted of a faint notch and ventral ridge showed sternal spine. The shoulder girdle comprised of three bones namely scapula, coracoid and furcula. Together these bones formed foramen triosseum by their proximal ends. Scapula was in the shape of a sword directed backwards and parallel to the vertebral column. It displayed a proximal extremity and a shaft. Proximal extremity unveiled lateral facet, coracoid process and a medial process. The shaft of scapula was smooth on both lateral and medial surface. Proximal extremity of coracoid was hook like and presented two processes viz. procoracoid and acrocoracoid. A rounded articular cavity was present at the base of procoracoid process. An articular facet was present just below the acrocoracoid process.A foramen was present at the junction of shaft and base of procoracoid.at an obtuse angle with respect to each other. The furcula was in the form of U shaped structure.Each clavicle of the furcula presented proximal extremity, ramus and a distal extremity.Lack of very distinct pneumatisation in both the sternum and shoulder girdle of red wattled lap-wing suggests its weak flying ability.