Bones from the atavistic hind-limbs of a humpback whale. A. From top to bottom, the cartiliginous femur, tibia, tarsus, and metatarsal, arranged as found in situ in the whale. B. Enlarged detail of the femur and tibia shown in A. (scale is not the same as A). C. Detail of the tarsus and metatarsal shown in A. (Image reproduced from: Andrews, R. C. (1921) "A remarkable case of external hind limbs in a humpback whale." Amer. Mus. Novitates. No. 9. June 3, 1921, Figures 2, 3, and 4.)

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