u/Spiritual_Border8811

So I know more Mega Stones will appear back at the Lab, but Ive looked through the list of Mega Stones and the PokeDex and I dont see any mention of a Tyrantrumite? I wanna use Mega Tyrantrum but as far as I can tell, its Mega Stone doesnt exist? Anyone know where its located at or if itll appear back at the University?