Polar forests of the Cretaceous Polar forests of the Cretaceous Cretaceous polar forests were temperate forests that grew at polar latitudes during the final period of the Mesozoic Era, known as the Cretaceous Period 145–66 Ma. During this period, global average temperature was about higher and carbon dioxide (CO) levels were approximately 1000 parts per million (ppm), 2.5 times the current concentration in Earth's atmosphere. The abundance of atmospheric carbon dioxide had a very significant impact on global climate and Earth's natural systems as its concentration is considered one of the main factors in the development of a pronounced greenhouse Earth during the Cretaceous with
T-Rex: Back to the Cretaceous continued for two weeks on location in Dinosaur Provincial Park. Yet the filmmakers faced a challenge in finding a realistic environment to set the live-action filming portion for the Cretaceous period sequences when Ally finds herself wandering amidst the lush vegetation of 66 million years ago. The location used to film Cretaceous period scenes in the end was in the Olympia rain forest in upper Washington state. The special considerations that must be made when working with IMAX 3D presentation also made it crucial that the background features of the shooting locations were ideal. Besides shooting locations, extensive computer-generated imagery