Gary Ross Dahl, 78, the creator of the wildly popular 1970s fad the Pet Rock, has died. His wife, Marguerite Dahl, confirmed Tuesday that her husband of 40 years died March 23 of chronic obstructive pulmonary disease.

The smooth stones came packed in a cardboard box containing a tongue-in-cheek instruction pamphlet for "care and feeding." Mr Dahl estimated he had sold 1.5 million of them at roughly $4 each by the time the fad fizzled.

Born in Bottineau, N.D., Mr. Dahl was raised in Spokane, Wash. In 1975, he was a Los Gatos, Calif., advertising executive when he came up with the Pet Rock idea. He also penned Advertising for Dummies. - AP