Which of the following is not found in birds?

Explanation

Forelimbs are absent in birds as they are modified into wings for flight. They are attached high on the back, to the anterior or thoracic region of the trunk, and are very powerful when compared with the size and strength of the bird. Each wing is elongated, flattened and distally pointed with its longitudinal axis at right angles to that of the trunk. The hindlimb is made of three parts i.e the thigh, shank and foot. The pectoral girdle on each side consists of three bones i.e a large coracoid, scapula and clavicle. The pelvic girdle consists of the ilium, ischium and pubis.