Fossils – Evidence of the Past

1. Fossils – Evidence of the Past • Grade 5 – Unit 6, Lesson 2 • Lesson Synopis • In this lesson, students will focus on how fossils are evidence of past life rather than creating models of fossils. This concept moved from Grade 4 and is a supporting standard for the Grade 8 STAAR exam. Students will research for the evidence for fossils and build the diorama as a model of the animal, plants, and environment of the same time period. Students do not have to know the geologic time scale but should recognize that changes generally take a long time to occur. • TEKS: • 5.7 Earth and space. The student knows the Earth’s surface is constantly changing and consists of useful resources. The student is expected to: • 5.7D Identify fossils as evidence of past living organisms and the nature of the environments at the time using models.

2. Vocabulary • Extinction • Environment • Fossil • Organisms • Prehistoric • Models • Evidence • Diorama

3. Fossils • Fossils tell the story of changes in life on Earth and changes in climate and atmosphere. Fossils also indicate the profound effects that environmental changes have had on living things. • Fossils are the remains or traces of ancient life. Fossils can be mineralized bones, teeth, shells, wood, or actual unaltered material from an organism, like frozen mammoth flesh, bones and fur. Eggs, nests, footprints, leaf impressions, burrows, and feces are examples of trace fossils. One thing all fossils have in common, they are OLD, at least 10,000 years old. • Fossils are found in sedimentary rock.

7. Extinction • The end of an organism or of a group of organisms, normally a species. The moment of extinction is generally considered to be the death of the last individual of the species.

8. Prehistoric •   The time before recorded history.

9. MYA • Million Years Ago

10. Information • Dating of rock and fossil layers help place past organisms and events in their proper time. • Dating is based on the fossil bearing layers of rock that form natural units with older layers on bottom and younger layers on top. • Scientists can calculate the age of materials within 2-10 million years. • In terms of geologic time, this margin of error is very small. An isotope of oxygen that is found in fossilized teeth indicates what the atmosphere was like. • Teeth can give information about the type of food an animal eats, which also indicates the habitat the animal lived in.

11. Information • Changes in sea level are indicators of climate changes. Marine fossils found in areas like current desserts or mountains were once living in water. • Sea level is a very important factor to both marine and terrestrial life. • Most marine species live in the shallower water that borders the continents.

12. Information • Tectonic plate motion contributed to the environmental changes including which areas of the Earth were in the landlocked interior or along a coastline. • The mountains, valleys, and other landforms created by geological process affect climate as well as the ocean.

13. Visit these websites: • Fossils For Kids - Shows fossil with past & present animals • Sands of Time - Shows a geologic time scale with pictures of organismsFossil Galleries– Photos of fossil remains of plants and animals • Dinosaur Gallery – Pictures of past animals and time periods • Stories from the Fossil Record– Tour modules to see how life and environments have changed • Earth Floor - Geologic Time – Climate, life, environments of the four Eras of time • Paleontology Portal - Information about various fossils and Texas fossils • Geologic Time Line – Information about animals, land formations, climate and more.

14. Engage • Imagine that you are in a time machine and you can visit any prehistoric time period • You exit the time machine and see many different types of plants and animals • These plants and animals are extinct today – so they might look different than anything you have seen • Share with the class one plan or animal you see in this past environment.

15. Explore – Ordering Fossils • In what ways do fossils provide evidence of organisms from the past? • What can a fossil tell us about the animal and its environment? • Why are fossils found primarily in sedimentary rock?

17. Trilobite Fossil • Photograph by James L. Amos • Trilobites, like this perfectly preserved specimen at South Dakota's Black Hills Institute of Geological Research, were among the most successful organisms ever to populate Earth. These familiar marine arthropods first arose about 545 million years ago in the early Cambrian and thrived throughout the world's oceans until they were wiped out in the Permian extinctions about 250 million years ago.

19. Swimming Nautilus • Photograph by Stuart Westmoreland • Nautiluses, like this one swimming in the waters off Palau, Micronesia, have changed little in their 270-million-year history. The first nautiluses appeared during the Permian period and were among only a handful of organisms to survive the widespread extinctions that wiped out nearly 95 percent of life on Earth about 250 million years ago.

22. Ginkgo Leaves • Photograph by TongRo Image Stock/Alamy • Ginkgo biloba is the only remaining species of the Ginkgoales order, which arose at the beginning of the Permian, some 280 million years ago. Also called the maidenhair tree, Ginkgo biloba trees can reach 100 feet (30 meters) in height and live more than a thousand years. Leaves from this living fossil are widely used in herbal medicines.

25. The Synthetoceras roamed around the grasslands of what is now Texas

29. A tropical prehistoric scene with several dinosaurs, including two spinosauruses, a psittacosaurus and two dorygnathuses in flight.

32. Prehistoric desert plant

33. Camel – Prehistoric desert animal