Born in Egypt in 1948, Tatossian immigrated with is family to Montreal in 1960 where he studied under Serbian sculptor, José Majzner, Adam Sheriff Scott from 1966 to 1969. He studied art history at McGill University from 1967 to 1969 followed by training as a muralist in Italy in 1970. He also studied with Jean Carzou in Paris in 1971 and painted with Jean Paul Riopelle in 1975.
In 1973, Tatossian became the youngest member accepted into the Royal Canadian Academy. He exhibited in North America, Europe and Asia, and his work can be found in the collections of the Montreal Museum of Fine Arts, the National Gallery of Canada and the Musée national des beaux-arts du Québec, among others. Tatossian died in Montreal in 2012.