Maria and Daria ('Masha and Dasha') Krivoshlyapova (Мария и Дарья Кривошляповы) (3 January 1950 – 17 April 2003, Moscow) were "Ischiopagus tripus" conjoined twins from Russia.

They were removed from their mother's custody at birth to be studied by Soviet physiologists. Their mother was told that her daughters had died soon after their birth.

In 1964, news spread to Moscow that a girl with two heads was being kept in the Institute. As a result, the twins were transferred to a boarding school for children with motor-impairment in Novocherkassk, southern Russia, to continue their education.

They studied here for four years in what they later recalled was the happiest time of their lives. In 1968 their third leg was amputated in an effort to make them less noticeable to the Soviet public, who were not used to seeing disabled people.

The twins had by now developed very different personalities, with Masha being dominant, tomboyish and cheeky, and Dasha submissive, thoughtful and quiet. Dasha fell in love with a fellow student, but Masha put a stop to the romance. Dasha fell into a depression and tried to hang herself when the pair were 18. This coincided with having been told by a medical commission which graded disability that they had been placed in the lowest grade, which meant that they would be kept for life in a retirement home (there were no homes for the disabled as the Soviet Union saw 'invalids' as flaws in the system) with no right to work or be independent in any way.

In 1989, aged 39, they moved into the 20th Home for Veterans of War and Labour and lived there in a small room with a single bed for the next twenty years. They earned pocket money sewing diapers and assembling pipettes.

They found their birth mother Yekaterina Krivoshlyapova in 1985 and she visited them for four years before Masha broke off the connection. They were visited every week by ‘Aunty Nadya’ – Nadezhda Gorokhova – their physiotherapist in TSNIIPP, who befriended them throughout their lives.

With the coming of Gorbachev’s campaign of openness, or ' glasnost' ' they made an appeal on a national television chat show Vzglyad in 1988, to be allowed to leave the 20th Home which was being turned into a mental asylum. The appeal was successful and they moved to the 6th Home for Veterans of Labour with greatly improved living conditions and bought themselves luxuries such as a television set, an Atari, a music cassette player and a computer on the proceeds of charitable contributions.