Squeaks and Mister Brown pretend to go back in time to learn more about Trilobites, using special clues from fossils! Second Grade Next Generation Science Standards Crosscutting Concepts Patterns: Observed patterns in nature guide organization and classification and prompt questions about relationships and causes underlying them. Science and Engineering Practices: Constructing Explanations and Designing Solutions Disciplinary Core Ideas: LS4.D: Biodiversity and Humans - There are many different kinds of living things in any area, and they exist in different places on land and in water (2-LS4-1). 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 Expectations: 2-LS4-1. Make observations of plants and animals to compare the diversity of life in different habitats. 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). 2-ESS1-1 Use information from several sources to provide evidence that Earth events can occur quickly or slowly.