ECOLOGY AND BIOLOGY OF THE PACIFIC WALRUS 



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Fig. 73. Annular ridges on the roots of tusks from free-living Pacific walruses. White dots 

 indicate position of each ridge on tusks of three males about 7 (left), 10 (center), and 

 25 (right) years old. Scale is centimeters. (Photo by F. H. Fay) 



