Many Twitter users wondered why top British model Cara Delevingne was cast to play Margo in the film adaptation of John Green’s novel “Paper Towns.” Those who commented were generally upset to hear the 22-year-old stunner was cast in the film because she isn’t what people imagined Margo would look like. Speculation over the casting turned the character name "Margo" into one of Tuesday's top-trending Twitter topics.

Twitterati took to the 140-character social media site to express frustration over the casting decision. Some of the comments have been posted below:

Though she is better known for the catwalk, Delevingne has nine credits on the Internet Movie Database. The site wrote she is best known for her appearance in the 2012 drama “Anna Karenina,” which won an Oscar for Best Achievement in Costume Design.

Even if fans aren’t happy about seeing the British model in the role, the “Paper Towns” author is thrilled. Green, whose novel “The Fault In Our Stars” was turned into a movie, which famously starred Shailene Woodley as Hazel and Ansel Elgort as Augustus, made the announcement on Twitter Tuesday. He said it was “very exciting.”

The model responded and said she was also enthusiastic about her new role.

Jake Schreier will direct the film about a boy who tries to uncover clues about the girl he admires, Variety wrote. Marty Bowen and Wyck Godrey are slated to produce the film and Scott Neustadter and Michael H. Weber were brought on the team to write the script. 

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