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    11 Things You Probably Didn't Know About America's First Zoo

    For starters, it's 140 years old today.

    On July 1st, 1874, the Philadelphia Zoo opened its gates for the first time.

    Here are some little known facts about America's First Zoo:

    1. Leo, the MGM lion, retired at the Philadelphia zoo after a 15 year long movie career.

    2. The Philadelphia Zoo had the first zoo-born cheetahs, orangutans and chimpanzees.

    3. The zoo recently unveiled Big Cat Crossing, the world's first overhead passage system that allows animals to roam the zoo via mesh-covered trails.

    4. When the zoo first opened, admission was 10 cents for children and 25 cents for adults.

    5. The zoo would have opened much earlier had it not been for the Civil War.

    6. The male Alligator Snapping Turtle who resides at the Philadelphia Zoo is said to be at least 100 years old.

    7. The first animal to arrive at the zoo was a raven. It arrived in 1873, shortly before the zoo's opening.

    8. Syfy's series Ghosthunters covered the Philadelphia Zoo and found ghost activity in several buildings.

    9. The animal who has been with the zoo the longest is a Galapogos Tortoise named Mama. She arrived at the Zoo in 1932.

    10. Dr. Ellen Corson-White, who was a scientist at the Philadelphia Zoo, developed the first scientifically-controlled diet for zoo animals.

    11. At one point, the zoo had over 3000 animals.

    Happy Birthday Philadelphia Zoo!