i only were able to bring em out once,for indominus rex i remember i killed an alpha allosaurus then,his death brought an alpha rex and alpha rex's death brought out an alpha indominus rex,and for space panda prime megatherium's death popped out a spacepanda with the text of saying "are you too old to play?" or something like that,but what im curious is i been killing so much prime megatheriums and alpha rexes but neither alpha indominus rex nor spacepanda has spawned since the one time i killed each of them once,is it one time per server?or what am i doing wrong?