<div>The shoulder girdle gives strength and range of motion to the wings of birds and plays a functional role in flight mechanism of birds. The present study was designed to compare the morphological features of shoulder girdle bones in crested serpent eagle and brown wood owl. The shoulder girdle comprised of the scapula, coracoid and fused clavicle i.e. furculum in both species. The proximal extremities of bones of shoulder girdle formed a foramen triosseum in both the species for tendon of supracoracoideus muscle. The proximal end of the scapula of crested serpent eagle presents a pneumatic foramen which was absent in the brown wood owl. The coracoid of crested serpent eagle presents a large pneumatic foramen at the medial surface of the acrocoracoid process. A piercing type of foramen was characteristic in the coracoid of both species. Procoracoid process was triangular in shape with a broad base in both the species with pointed apex in brown wood owl and short apex in crested serpent eagle. The clavicle was thin, slender and highly curved in crested serpent eagle, whereas it was slender and rod-like in brown wood owl. Numerous pneumatic foramina were present in the proximal extremity of the clavicle of the crested serpent eagle, which were few in brown wood owl. The distal extremity of both clavicle fused to form a hypocleideum in crested serpent eagle, which was absent in brown wood owl.&nbsp;</div>


<div>Comparative gross anatomical studies on the shoulder girdle of crested serpent eagle (<em>Spilornis cheela</em>) and brown wood owl (<em>Strix leptogrammica</em>)</div>


<div style="text-align: justify;">The present study was conducted on the scapula of five adult tigers to record the characteristic features of scapula bone. It was placed on lateral aspect of thorax, directed downward and forward. It was in the form of wide plate having scapular spine on lateral aspect. The height of spine increased gradually towards the distal end. The acromian process was subdivided into hamate process and suprahamate process. Hamate process overhanged the glenoid cavity. The suprahamate process was in the form of thin triangular plate directed backwards. The supraspinous fossa presented undulating surface in its middle. The infraspinous fossa was triangular and more or less flattened. Subscapular fossa was shallow and presented two prominent ridges. The caudal angle of the scapula was terminated in to glenoid cavity which was oval to quadrangular in shape. Cranial and proximal to the glenoid cavity prominent supraglenoid tubercle was observed which had hook shaped coracoid process. Scapula of both the sides were morphologically similar but the morphometrical values for the right scapula were non-significantly higher than the left counterpart (t&lt; 0.05), which may be of some biomechanical importance.</div>

Gross anatomy of scapula in Tiger (<em>Panthera tigris</em>)

<div style="text-align: justify;">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.</div>

Comparative gross anatomical studies on the shoulder girdle of crested serpent eagle (Spilornis cheela) and brown wood owl (Strix leptogrammica)

Gross anatomy of scapula in Tiger (Panthera tigris)

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