Saber Tooth — Lou Cadle

A time gate... A team of teen scientists... A desperate fight to survive.... Park Ranger Hannah Kates is leading a group of gifted teens on a fossil-hunting field trip when a rock slide uncovers a portal through time. The fossil hunters are whisked back to an era when giant predator mammals roamed the earth. They want, desperately, to find their way home. But first, they have to survive a world where bizarre--and hungry--mammals ruled North America. They have to survive the Dawn of Mammals. In Book 1 of the series, they are thrown back thirty million years to the world of saber-toothed nimravids, ferocious carnivores. Hannah and the nine teens will have to adapt quickly to learn the skills they'll need to survive this vicious world of tooth and claw.