Image via Wiki and is part of the public domain.
Caption: "The last known Thylacine photographed at Hobart (formerly Beaumaris) Zoo in 1933. A scrotal sac is not visible in this or any other of the photos or film taken, leading to the supposition that "Benjamin" was a female, but the existence of a scrotal pouch in the Thylacine makes it impossible to be certain."
(See also: Portrait of Benjamin, a Thylacine. on easyvegan.info.)