The bones of the forelimb of a walrus ( Odobenus rosmarus ) showing measurements used in the study of lateralized limb use. (Photo by Anders Galatius). I: The four measured bones are marked. II: Measurements of the scapula. A: Length, B: Height. III: Measurements of the humerus. A: Epiphyses unattached, B: Epiphyses attached. IV: Measurements of the radius. A: Epiphyses attached, B: Epiphyses unattached. V: Measurement of ulna, epiphyses unattached.