In the scene where Bones and Carol are about to open one of the seventy-two missiles to prove Khan's claim that there's more then just a missile inside, Bones mentions that he once performed a emergency C-Section on a pregnant Gorn, noting "those little bastards bite!" This is reference to an off-screen event in the video game tie-in
Star Trek (2013), where Sulu stuns a pregnant Gorn, and Bones performs said C-Section.