Officials at the Cleveland Metroparks Zoo say it can be tough to establish the sex of a giant Aldabra tortoise because the reproductive organs normally aren't visible. But Mary's maleness was unexpectedly revealed earlier this month during a routine exam.
When the 400-pound tortoise arrived at the zoo in 1955, it was assumed he was a she because of a flatter shell, shorter tail and all-around smaller size than most males.
Mary is estimated to be between 75 and 100 years old.
Zoo Director Steve Taylor is considering whether the senior citizen deserves a new name.