I picked up this book that was gathering dust on my shelf today.
"The Doomsday Book of Animals" by David Day.
It's simply about extinct animals, from recent history. It gives great details and a few illustrations.
I find myself amused and disappointed that I never thought to use it as a reference for gaming before. It's full of interesting animals that would add a lot of color and interest to a game.
If you get the chance (and are lucky enough to find a copy) check it out. It's worth it!
The Doomsday Book of Animals
by David Day
Viking Press, New York
ISBN: 0-670-27988-9 (pbk)