Maureen Thornton (born 30 May 1946; age 78) is the actress who, together with her twin sister Colleen, appeared as the Barbara series androids in the Star Trek: The Original Series second season episode "I, Mudd". She filmed her scenes on Wednesday 16 August 1967 at Desilu Stage 10.
She also had a role in Coogan's Bluff (1968), together with her sister and Seymour Cassel, Albert Henderson, Andy Epper, and Allen Pinson.
During the late 60s, the Thornton sisters became known as singers, and for a time, belonged to a troupe that performed the musical Hair: The American Tribal Love-Rock Musical. The sisters, identified as "The Gemini Twins" of Hollywood, were ejected from Acapulco, Mexico, in early January, 1969, for performing their production while only carrying a tourist visa. ('Mexican Authorities Cut Play Hair Short', Playground Daily News [Forth Walton Beach, FL], 9 January 1969, p. 20.)
In 1970, both sisters attended the Jimi Hendrix concert on Maui, with Maureen appearing in the music documentary filmed during the concert, Rainbow Bridge (1972). Footage of both sisters at the concert later appeared on the 2020 Blu-Ray/DVD release of Live in Maui.
Maureen's acting career was sporadic during the 1970s, where she appeared in an episode of Barlow at Large (1973), an episode of Play for Today (1977), and the adventure film Pilgrim's Progress (1978).
In addition to her acting roles of the late '70s, Thornton doubled as a singer and songwriter, appearing as a backing vocalist and writer on several songs in her sister's band, Fortune's debut album, Fortune (1978). Both sisters also appeared on the album's cover.
In 2002, Thornton made her final acting appearance in the the short film drama, The Silence of Robert Raskin.