Takashi Tezuka and Shigeru Miyamoto were the first designers who made up R&D4 (EAD). Super Mario Bros and The Legend of Zelda were co-designed by the two men. Tezuka directed The Legend of Zelda III, Super Mario World, Yoshi's Island, Super Mario Bros. 3, The Legend of Zelda: Link's Awakening.
Just like Miyamoto stopped directing games in 90s, Tezuka stopped directing after Yoshi's Island. They are both producers now. While at first Tezuka was acting as a co-producer with Miyamoto, Miyamoto and Tezuka now tend to produce games independently of each other. Animal Crossing and Yoshi Touch N' Go had no involvement from Shigeru Miyamoto. Right now the guys directing the games at EAD, are the younger designers who first started making EAD games on the N64. Most of the designers (2nd generation EAD guys) who started late NES/SNES are now producers and assistant producers as well. (Eiji Aonuma, Hideki Konno, Tadashi Sugiyama, etc)