Frederica Sagor Maas, one of the last surviving screenwriters, if not the last, with credits dating back to Hollywood’s silent era, died Thursday in La Mesa, Calif., of natural causes. She was 111.

Maas contributed to the screenplays of 15 films from 1925-28. She was an uncredited contributor to the Greta Garbo-John Gilbert classic “Flesh and the Devil” and to the Clara Bow starrer “It,” but perhaps most significantly, she earlier co-adapted “The Plastic Age,” a 1925 hit film that proved a huge career break for Bow.

Maas felt repeatedly misused by the film industry and detailed her unhappy experiences in the 1999 memoir “The Shocking Miss Pilgrim: A Writer in Early Hollywood,” published when she was 99.

In the wake of the success of “The Plastic Age,” she was signed to a contract at MGM, where she claimed others took credit for her work, including “The Waning Sex”; her contract was not renewed. At Tiffany Prods. she drew credits on flapper comedies “That Model From Paris” and “The First Night.”

She married Fox-based producer Ernest Maas in 1927, after which they teamed on scripts, but she soon found frustration again. She scripted “Silk Legs” for Fox and worked for Paramount on Bow pictures “It,” “Red Hair” and “Lula” as well as the Louise Brooks film “Rolled Stockings.” But a script they wrote called “Beefsteak Joe” was, she claimed, misappropriated and made into the Victor Fleming-directed Paramount film “The Way of All Flesh” (unrelated to the novel of the same name), and Maas found that her career momentum had slowed considerably after the couple returned from an extended European vacation. She was credited on Fox’s rural comedy “The Farmer’s Daughter” but hated the assignment.

The Maases could only get rewrite work in the early 1930s. In 1935 “Silk Legs” was remade, in Spanish, by Fox, and the couple reviewed plays for the Hollywood Reporter from 1934-37. They continued to write screenplays but couldn’t get them produced; in 1941 she wrote “Miss Pilgrim’s Progress,” a sober treatment of women in the workplace that sold for a song and eventually became Fox’s 1947 pic “The Shocking Miss Pilgrim,” a lighthearted musical comedy vehicle for Betty Grable. The couple eventually considered suicide, and Frederica Sagor Maas eventually became an insurance adjuster.

In her 1999 book, which film historians consider an important reference on the inner workings of early Hollywood, she was harshly critical of legendary figures including Louis B. Mayer and Irving Thalberg and of the pervasive sexism and chicanery she repeatedly encountered in the industry.

Born in New York City to Russian immigrant parents, Frederica Sagor attended Columbia College, from which she was hired away in 1920 by Universal Pictures to be an assistant story editor; the job involved attending Broadway plays to determine whether the material was suitable for bigscreen adaptation. She moved to Hollywood, eventually, because she wanted to pen scripts herself.

Ernest Maas died in 1986 and the couple had no children.