Latching mechanisms in multiple embodiments connect clamshell type couplers comprising a pair of arcuate coupling halves joined at a hinge. One embodiment includes a biased catch lever that engages a corresponding latch plate. Another embodiment includes a plurality of latching extensions that engage an opposing latching housing, along with biased locking buttons for selectively locking the mechanism. Another embodiment includes dual rotatable latching arms for interconnecting the coupling halves, each arm having a latching cam for selectively locking the mechanism. Another embodiment includes a rotatable latching arm and a receiving bracket for receiving the latching arm for selectively locking the mechanism. Another embodiment includes an over center hinge mechanism including three cooperating and rotatable latch plates. Another embodiment includes cooperating cassette mechanisms, each having connector extensions for connecting the cassette mechanisms to one another for selectively locking the mechanism. Methods are also disclosed for selectively locking the latching mechanisms.