There's lots of talk (and some litigation) over ageism in Hollywood with regard not just to actors and actresses, but to directors, writers and other talent. In a lawsuit filed Monday, an assistant director who worked on The Big Bang Theory is joining the conversation.

Christopher Klausen filed suit in Los Angeles Superior Court against Warner Bros. Television, which produces the CBS sitcom. He claims the studio and members of the production staff reduced his work on the series over several seasons and illegally terminated him after the eighth season.

Fifty is the magic number in Klausen's lawsuit. He claims it was after he hit his 50th birthday that the crew conspired to cut him out of the production.

With credits from Diff'rent Strokes and The Fresh Prince of Bel Air to Fox's ill-fated Dads, Klausen has worked as a second assistant director or stage manager (the positions are similar, his complaint states) and first assistant director in television for more than 30 years. He started working on The Big Bang Theory as a second assistant director on the pilot, which aired in 2007.

His complaint doesn't cover the years between then and 2012, when he turned 50. With the show's sixth season in 2012, he says, the producers reassigned his duties of interacting with the actors to Nicole Lorre, "who was in her early-to-mid twenties," and T. Ryan Brennan, "who was in his early thirties."

It wasn’t just the crew, says Klausen. "Mr. Klausen noticed that the stars of the show, which are all considerably younger, began to ostracise [sic.] him after he turned fifty (50) years old," states the complaint. Read it here.

He claims when he asked producer Faye Oshima Belyeu why his duties were assigned to others, she told him they "related to the actors better." States his complaint, "The only reason that Ms. Lorre and Mr. Brennan 'relate[d] to the actors better' are because they are younger than Mr. Klausen."

Klausen says with the seventh season, he went from second assistant director to the uncredited position of second second assistant director, and his duties were reduced to blocking the actors. Also during the production of the seventh season, Klausen several times was asked to stand in for the first assistant director, which he says demonstrates his alleged lessening of responsibilities was not caused by poor performance on his part.

After the eighth season of the series (which CBS has renewed through season 10, when the principal cast, including Johnny Galecki, Kaley Cuoco and Emmy winner Jim Parsons, will receive $1 million per episode due to contract renegotiations in 2014), Klausen says Oshima Belyeu fired him. He claims during the phone call terminating him, she could not provide instances in which his performance was insufficient. He's forced to conclude he was fired for his age, he says.

Represented by Michael J. Bononi, Klausen claims violation of California's Fair Employment and Housing Act, failure to prevent discrimination and wrongful termination.

Aug. 17, 9:16 p.m.: Warner Bros. declined to comment.