An excavation tooth lock assembly to lock a first tooth member to a second tooth member, the first tooth member having a body that incorporates a socket which is configured to receive a nose portion of the second tooth member, a locking space provided when the second tooth member is received in the first tooth member, wherein the lock assembly comprises: a lock comprising a body which is configured to be inserted into the locking space including by rotating the body into an operative position to lock the first tooth member to the second tooth member and interengaging elements disposed on the lock and one or both of the first and second tooth members, the elements configured to releaseably retain the lock within the locking space in its operative position.