An intervertebral fusion implant for the fusion of two vertebrae comprises an upper bearing body for placing on a lower end-plate of a vertebra, a lower bearing body for placing on an upper end-plate of a vertebra, and a central piece arranged between the bearing bodies. The central piece comprises a claw coupling which, in a coupling position, couples the two bearing bodies in a rotationally fixed manner to each other. In an open position of the claw coupling, the bearing bodies are freely movable in relation to each other. The claw coupling is actuated automatically via a plastic blocking body which, in its initial position, holds the claw coupling open and, under a load transferred from one vertebra to the other vertebra, is slowly deformable until it reaches a final coupling position in which the claw coupling is closed. This results in the slow fusion of the vertebrae.
