Titanoboa: Journey to the Amazon, Paperback

Professor Hank Newstead has been making expeditions to the Amazon River for years. They've become routine to him. But this time, the expedition is going to be anything but normal. Hank, along with a hardened river boat captain, his much younger girlfriend, and his main professional rival, are in the Amazon purely to study frogs. All their plans vanish quickly, however, when they are attacked by a Titanoboa, an enormous prehistoric snake that should be millions of years in its grave. As their crew dwindles from a series of terrifying attacks, they discover a secret: a long lost colleague of the professor has taken up residence on an island in the deepest parts of the jungle. And if Hank and the others can't find and stop her, then the Titanoboa will not be the only extinct monster unleashed back into the world.