Child safety seat assemblies

A child safety seat assembly (100) includes a support base (104) and a child carrier (102). The support base includes a shell body (114), an anti-rebound frame (130) and a latch (138). The shell body has a bottom surface (114C) that supports the support base when resting on a support surface, and an upper surface (114D) for installing a child carrier. The anti-rebound frame is assembled with the shell body, the anti-rebound frame being movable up and down relative to the shell body to extend upward past the upper surface and to extend downward past the bottom surface. The latch is operable to lock the anti-rebound frame with the shell body.