An implant and method for fusing adjacent spinal vertebrae is disclosed. In an embodiment for a spinal implant of the present invention, the implant includes a spacer body assembly and two retention members. The two retention members each include split fork tangs wherein the tangs of each retention member are simultaneously extendable from the spacer body assembly into the adjacent vertebra. A method of fusing adjacent vertebrae includes the step of inserting an implant between adjacent vertebrae with retention members. The method also includes the step of configuring the retention members wherein a portion of each tang of a retention member simultaneously extends from the implant into one of the adjacent vertebra.
