"I must applaud @angelicaross for her tour de force of performance as Candy Abundance Ferocity. It has been a gift to watch her blossom as a true star and undeniable talent," he continued.
"Though she will always be our Candy, and our show suffers this incredible loss, I am elated that the world will get much more Angelica," Murphy wrote.
"She is joining the American Horror Story family in another unforgettable role. Congrats Angelica for making history, leaping from #PoseFX to #AHS1984. Welcome to the #AHS family!"
Ryan's reference to Pose's "incredible loss" is in context to last night's episode in which Ross' character Candy was shockingly killed off.