Doctors Paul Sereno and Brady Barr are on the trail of a massive 35' ancient crocodile! Herpetologist Brady Barr, inveterate croc lover, wants to know a lot more about where his favorite creature came from and how it evolved. To find the answers he seeks out paleontologist Paul Sereno, who is out in the desert in the process of unearthing an incredible example of a huge, ancient crocodile that went by the name of Sarcosuchus. This show, originally a National Geographic Explorer special, takes you with these scientists as they wrestle with crocodiles and get up-close-and-personal with a variety of ferocious reptiles.