Long-time Paramount TV Studios executive Keith Cox is departing the company after 20 years. Cox, an early advocate for Taylor Sheridan and what would become the sprawling Yellowstone universe and former head of development and production at Paramount Network and TV Land, is currently president of MTV Entertainment. He and Paramount TV Studios president Matt Thunell announced Cox’s departure in notes sent to staff on Thursday (read them in full, below). “Keith is a respected leader and has been an incredible partner to both Dana [Goldberg, co-chair of Paramount Pictures and chair of PTVS] and me from our first days at Paramount,” Thunell wrote. “We are grateful for his leadership, collaboration, and the impact he has had on our teams, creative partners, and franchises.” Cox’s key lieutenants, Paramount TV Studios vps Todd Baynes and Antonia Covault, will move to the current series team at the studio, headed by executive vp Carolyn Harris.…