Dino stops by the Fort to learn all about dinosaurs with Jessi and Squeaks! Did you know that dinosaurs were on Earth for so long that not all dinosaurs lived at the same time?! 2nd Grade Next Generation Science Standards Science and Engineering Practice: Developing and using models Disciplinary Core Idea: ESS1.C: The History of Planet Earth - Some events happen very quickly; others occur very slowly, over a time period much longer than one can observe (2-ESS1-1). Performance Expectation: 2-ESS1-1 Use information from several sources to provide evidence that Earth events can occur quickly or slowly.