Structure of the skeleton

Forelimb:

The fore-limb used in swimming is probably the most striking adaptation to be found in the skeleton of a sea turtle. The radius and ulna are fused by connective tissue to make them more rigid. The fingers or digits have become elongated and stiffened by layers of fibrous tissue covered with scaly skin. The coracoid of the pectoral girdle is expanded for the attachment of the powerful swimming muscles (Wyneken J, 1997).