Gross morphological studies on the sternum of crested serpent eagle (Spilornis cheela)

The present study was designed to elucidate the morphological characteristics of sternum of crested serpent eagle. The sternum was a thin, flat bone with a body, rostrum and keel. The body was quadrilateral plate with concave dorsal and convex ventral surfaces and four borders. Numerous pneumatic foramina were present on the dorsal surface. The ventral surface presented a large, boat shaped keel along its median line. The cranial border was convex and thick and two pneumatic foramina were present behind the cranial border on the ventral surface of sternum. The facets for coracoid bones were located just below the cranial border. The lateral border on either side presented six articular facets for sternal ribs. The triangular pointed cranio-lateral process was observed at the junction of cranial and lateral border on either side. The caudal border was convex and caudo-lateral processes were absent. Two distinct oval foramina were seen near the caudal border. The rostrum or sternal spine was smaller and located just below the cranial border of the body of the sternum. The sternum presented a well-developed triangular keel located along the midline of the ventral surface of the body of sternum.