“Summer Olympics”: swimming, men’s gymnastics, U.S. beach volleyball (8 p.m.,

“Summer Olympics”: swimming, men’s gymnastics, U.S. beach volleyball (8 p.m., NBC): Michael Phelps swims for his first gold of these Games in the men’s 400IM at the visually stunning Water Cube. “Mr. and Mrs. Smith” (8 p.m., FX): Yes, the competition is fierce in the Olympics, but some of us would rather watch Brad Pitt and Angelina Jolie duke it out in the 2005 film “Mr. and Mrs. Smith.” Who knew gunplay could be a form of foreplay?

“Primeval” (9 p.m., BBC America): Douglas Henshall is running out of ways to look shocked no matter what kind of dinosaur is chasing him.

“The difference between a future predator, a gorgonopsid or a velociraptor [is] they are all going to hurt you really badly,” deadpans the British actor starring in the adventure import “Primeval,” about a team of researchers often faced with time-displaced dinosaurs. “So it’s difficult to kind of characterize them and maybe look slightly less scared or freaked out.” Henshall gets a lot of practice for expressions. On “Primeval” he plays professor Nick Cutter, whose team is exploring a series of wormholes opening time between the past, present and future. Often, those holes lead to a rogue dinosaur running into the present.