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.

Masha and Dasha's mother, Yekaterina Krivoshlyapova, did not know she was having twins and spent two days and nights giving birth naturally. The doctors told her she had delivered a mutant (урод) and she was not shown the babies. They were born joined at the waist at a 180-degree angle with two heads, two torsos, two arms and one leg each, and a third, vestigial limb at the back