What's the opposite of a cougar?

Rereading Gone With the Wind for about the thirteenth time and loving it, as always. However, for the first time I really noticed some of the ages mentioned, and was a bit taken aback. Gerald O'Hara is 43 when he marries Ellen Robillard, who is only 15. Suellen O'Hara's "beau" Frank Kennedy is 40 and she's 14. And Rhett Butler is mentioned as being 30 or 35 at the beginning of the novel and Scarlett is only 16.

For some reason this never struck me before, but even for the 1860s this seems rather a wide age disparity.