A container denester apparatus for sequentially supplying nested containers, the apparatus comprising an indexer chassis, an indexing assembly and a rotating indexing arm. The rotating indexing arm is configured to extend into the clamshell cavity, which provides for the passage of clamshell containers therethrough. The indexing arm is rotationally coupled to at least one of the at least one rack gear, and has a lower cam profile and an upper cam profile, with the cam profiles extending into the clamshell cavity when properly rotated. In a starting position, a clamshell container is precluded from passage through the clamshell cavity, and, a portion of an underside surface rests upon the upper cam profile. Through rotation of the rotating indexing arm the lower cam profile forces the downward movement of the clamshell container while retaining the other clamshell containers nestedly coupled thereto.