In: Biology
1. Skeletal modifications that assist with avian bipedal locomotion include:
A. uncinate process
B. expanded ilium
C. pygostyle
D. carina
bipedalism: moving on two legs which includes walking , running, hopping, jumping and skipping gaits.
all birds are bipedal, it is a feature inherited by the dinosaur ancestors.
uncinate process: extending from midpoint of the vertebral ribs, integral to mechanics of ventilation in birds, active in both inspiration and expiration. Also play role in locomotion. They have also occured in the theropod dinosaurs, proving that they are the ancestors of the birds.
pygostyle: final few caudal vertebrae fused into single ossification supporting the tail feathers and musculature. composed of several fused caudal vertebrae supports the retricial bulb and associated muscles and feathers for controlling tail fan and contour shape.
carina : also known as KEEL is a bird anatomy which is the extension of sternum (breastbone) running axially along the midline of the sternum while extending outward , perpendicular to the palne of ribs. one of the most obvious and important modification in the avain skeleton.
therefore the choices are : A, C, D