St. Louis — Sister Mary Timothy Ryan, SSND, died Aug. 17 at Anna House at The Sarah Community in Bridgeton, Mo. She was 97 years old.

Sister Mary Timothy was born in St. Louis and entered the congregation of the School Sisters of Notre Dame in 1931 from Blessed Sacrament Church in St. Louis. She professed first vows in 1934 and final vows in 1940. She majored in history at St. Louis University and earned a bachelor's in 1940, a master's in 1941 and a doctorate in 1952.

She began her teaching career at St. Francis Solanus in Quincy, where she taught from 1934-1938. She also taught at Holy Ghost, St. Louis, 1938-1939; Notre Dame High School, St. Louis, 1941-1946; and Rosati-Kain High School, St. Louis, 1949-1954. She was a professor at the former Notre Dame College in St. Louis, 1954-1962 and 1973-1977, and served in administration there as academic dean and dean of admissions from 1962-1973.

In 1977, Sister Mary Timothy inaugurated the Liturgy of the Hours with three other sisters at the National Shrine of the Immaculate Conception in Washington, D.C. A year later, she returned to the Midwest and served as coordinator of hospitality at the St. Louis motherhouse from 1978-1982 and in pastoral ministry at Immaculate Conception Parish in Mattoon from 1982-1996.

As a participant of The Nun Study through the University of Kentucky and the University of Minnesota, Sister Mary Timothy was one of 678 School Sisters of Notre Dame who helped scientists learn about the aging process and Alzheimer's disease. Researchers studied her early life, lifestyle, education, and physical and mental abilities. She donated her body to science to continue the research.

Sister Mary Timothy is survived by a sister, Grace Whalen of St. Louis.

A memorial Mass was held on Aug. 26 in the School Sisters of Notre Dame Theresa Center Chapel in south St. Louis County. Memorial contributions may be made to the School Sisters of Notre Dame, Resource Development, 320 E. Ripa Ave., St. Louis, MO, 63125-2897.