 Additional subfamilies have been named for more fragmentary genera , including Aublysodontinae and Deinodontinae . However , the genera Aublysodon and Deinodon are usually considered nomina dubia , so they and their eponymous subfamilies are usually excluded from taxonomies of tyrannosaurids . An additional tyrannosaurid , Raptorex , was initially described as a more primitive tyrannosauroid , but likely represents a juvenile tyrannosaurine similar to Tarbosaurus . However , as it is known only from a juvenile specimen , it is also currently considered a nomen dubium . 
