Cretaceous was an Metriorhynchus and one of the film's main antagonists.
Cretaceous is shown in the beginning frozen in a great block of ice that was loose when the wall of ice began crumbling. The ice melted, releasing both Maelstrom and him into the lake which was all but abandoned by most animals. When they made it to the ice lake, the first animal that they had encountered and eaten was Stu the glyptodont, leaving behind only his shell. The two sea reptiles then swam further down the series of rivers where they eventually reached Manny's herd as well as Crash, Eddie, and Ellie. Cretaceous made a great lunge at Manny, but was caught on his tusks, only to be flung far off, hitting a piece of ice and falling back into the water.
Later, when the dam broke, the two reptiles went swimming on the wall of water that was slowly approaching towards the escaping masses and pulled down Manny when he was swimming to save Ellie. Manny devised a plan to rid himself of the two sea reptiles, by having them try to chase him, he tricked them into hitting a log that was wedged under a large rock. The plan worked, freeing Ellie, and the boulder came down on the two reptiles. Although the two reptiles are presumed to have been crushed by the boulder, there might be a possibility that they may have survived the boulder and have gotten swept away with the flood water when Scrat broke the glacier.
|Ice Age (2002) • The Meltdown (2006) • Dawn of the Dinosaurs (2009) • Epilogue (2002) • Ice Age: Continental Drift (2012) • The Land Before Time/Ice Age crossover (2015)|
|The Land Before Time XIV (2010)|
|Manny • Ellie • Scratte • Buck • Peaches • Scrat • Sid • Diego • Crash and Eddie • Sylvia • Rudy • Momma • Shelly • Lone Gunslinger • Fast Tony • Jennifer and Rachel • Mini-Sloth • Roger • Ruby • Flightless Bird • Others|
|Ice Age • The Meltdown • Dawn of the Dinosaurs • Ice Age 4 • The Land Before Time XIV|