Deinosuchus

Deinosuchus (name meaning "terrible crocodile") is a genus of giant crocodilian that lived in North America during the late Cretaceous period. It might have preyed on both aquatic and terrestrial organisms such as sea turtles and fish, and large dinosaurs like hadrosaurs and theropods.

Portrayal in the series
Deinosuchus had the overall natural appearance of any crocodile; rough, scaly skin, long snout, legs spread out, teeth going up and down from jaws, etc. However, it was far larger than any crocodilian. Measuring 50 feet (15 m) in length and weighing up to 10 tons, Deinosuchus was the largest crocodilian of all time. They were also swampy green in color and had yellow eyes.

Though normally living in rivers and lakes, Deinosuchus, like many modern-day crocodilians, would venture out into the open oceans to find food. Deinosuchus also lived in numbers of five or six individuals.

Deinosuchus was capable of taking down Parasaurolophus. It did, however, have to contend with the large tyrannosaur Albertosaurus.

Supercroc
This crocodilian was the creature Nigel Marven planned to catch in Episode 6.

Nigel witnessed a Deinosuchus preying on a young Parasaurolophus. He later witnesses several Deinosuchus scare-off an Albertosaurus pack from their kill and builds a trap for the giant crocodilians. Unfortunately, several Troodon steal the bait instead, so Nigel is forced to bait the trap with himself. He is successful and captures a Deinosuchus before bringing it back to Prehistoric Park. The lake for the crocodile is just at the end of the time portal so Nigel grabs a big piece of meat and takes the crocodilian to the pool.

Finally, at the end of the episode, during the mass break-out, Matilda the T. rex chases Nigel, and, at one point, the captured Deinosuchus jumps out of the water and attacks Matilda, but misses, and gets fought off by the Tyrannosaurus rex. This however, gives Nigel more time to reach higher ground and escape Matilda.

Errors

 * Deinosuchus is not necessarily the largest known prehistoric crocodilian. Some of the genera that have been previously credited as being larger have recently been downsized, but Purussaurus mass estimates can still be higher.
 * Deinosuchus is more related to alligators than crocodiles.
 * Most Deinosuchus are thought to have been around 30 feet long, but isolated remains do suggest that some individuals could have approached 40 feet in length.

Trivia

 * It, along with the Terror Bird, were the only carnivorous vertebrates that Nigel successfully caught on his first trip to their time periods.