(Erroneously referred to as a Metriorhynchus in Ice Age Village)
|Affiliation||Partnered with Maelstrom|
|Behind the Scenes|
|Created by||Carlos Saldanha|
|Performed by||Hissing growls|
Cretaceous is a member of an unknown species of Ichthyosaur or possibly some marine crocodile. He was released from his icy prison alongside his partner, Maelstrom, during the meltoff.
Cretaceous and his fellow sea reptile, Maelstrom, are once creatures of the era of dinosaurs that have worked in tandem to catch prey. After having been frozen in the waters they swam in, both reptiles remain in stasis until the meltdown began, thawing them out into a world ruled by mammals instead of reptiles.
Like his larger companion, Maelstrom, Cretaceous is incapable of speech and so communicates in loud growls, hisses or roars. Cretaceous is a large ichthyosaur, thickly built with an elongated snout lined with many pointed teeth ideal for slicing into prey, faintly glowing yellow eyes, a spiny sail and tail equipped with a long fishlike fin, and armor-like purple scales that are topped off with small spikes and bumps. Cretaceous propels through the icy waters with two strong front legs and two small hind fins, the former of which could be used to haul himself on land or onto any surface should the need arise.
- True ichthyosaurs resemble dolphins more than crocodiles, with no armor-like skin, clawless limbs and a less crocodilian snout. This creature is based more off a crocodilian.
- Film director, Carlos Saldanha originally wanted to have three aquatic predators which one of the creatures appeared to be a axolotl, but the axolotl was scrapped in order to make two creatures more dangerous
- Ice Age: The Meltdown (First appearance)