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Biology of Sea Turtles, Vol. II
FIGURE 2.22 Diagrams of cheloniid right shoulder muscles, including locomotor and respiratory muscles. Superficial ventral muscles (top left), deep ventral muscles (bottom left), lateral
muscles (top right), and posterior muscles (bottom right). The extensor digitorum, extensor
radiali intermedius, tractor radii, and flexor carpi control the extension and flexion of the
flipper blade. Ext. = extensor; h. = head; inf. = inferior; interm. = intermedialis. The large
subscapularis covers most of the scapula; it protracts the flipper. The latissimus dorsi, a large
sheetlike muscle, plus the teres major and deltoideus scapular head abduct and sometimes
protract the flipper. The large coracobrachialis is seen ventrally, covering much of the procoracoid. The biceps superficialis extends from the shoulder (mostly the procoracoid) to the
pisiform bone of the wrist, and probably helps control the twist or rotation of the flipper blade.
The biceps profundus acts as a flipper retractor and a flexor of the flipper blade at the elbow.
The two heads of the triceps brachii (triceps scapular head and triceps humeral head) are
forelimb adductors. (Adapted from Wyneken, J. The Anatomy of Sea Turtles, U.S. Department
of Commerce, NOAA Technical Memorandum NMFS-SEFSC-470, 2001. With permission.)
1123_C02.fm Page 66 Friday, November 15, 2002 11:16 AM
Biology of Sea Turtles, Vol. II
FIGURE 2.22 Diagrams of cheloniid right shoulder muscles, including locomotor and respiratory muscles. Superficial ventral muscles (top left), deep ventral muscles (bottom left), lateral
muscles (top right), and posterior muscles (bottom right). The extensor digitorum, extensor
radiali intermedius, tractor radii, and flexor carpi control the extension and flexion of the
flipper blade. Ext. = extensor; h. = head; inf. = inferior; interm. = intermedialis. The large
subscapularis covers most of the scapula; it protracts the flipper. The latissimus dorsi, a large
sheetlike muscle, plus the teres major and deltoideus scapular head abduct and sometimes
protract the flipper. The large coracobrachialis is seen ventrally, covering much of the procoracoid. The biceps superficialis extends from the shoulder (mostly the procoracoid) to the
pisiform bone of the wrist, and probably helps control the twist or rotation of the flipper blade.
The biceps profundus acts as a flipper retractor and a flexor of the flipper blade at the elbow.
The two heads of the triceps brachii (triceps scapular head and triceps humeral head) are
forelimb adductors. (Adapted from Wyneken, J. The Anatomy of Sea Turtles, U.S. Department
of Commerce, NOAA Technical Memorandum NMFS-SEFSC-470, 2001. With permission.)
1123_C02.fm Page 66 Friday, November 15, 2002 11:16 AM