YOU HAVE 3 MINUTES TO GET YOUR MATERIALS and FIND YOUR SEAT!! To be successful today, YOU need: pen/pencil, Do Now half sheet, Notes sheet, chromebook YOU HAVE 3 MINUTES TO GET YOUR MATERIALS and FIND YOUR SEAT!! EXPECTATIONS for Do Now (on half-sheet): Sitting in YOUR assigned seat… SILENTLY and INDEPENDENTLY… COMPLETE your Do Now… We have 29 days to the EOG - What POSITIVE choices can YOU make today??

→ Go to www.sciencewithmissb.weebly.com → Click on the “Classwork” tab → Under “Week 30 - Earth History Review” → Download Day 3 - Fossils.ppt Go through the powerpoint and fill in your guided notes. Complete the interactives at the end of the powerpoint.

LEQ: How do scientists use fossils to understand how the Earth has changed over time? (Standard 8.L.1.2) 3

What is a fossil? What do fossils tell us? A fossil is the preserved remains of a once-living organism. What do fossils tell us? Fossils give clues about organisms that lived long ago. They help to show that evolution has occurred. They also provide evidence about how Earth’s surface has changed over time. Fossils help scientists understand what past environments may have been like. 4

HOW IS A FOSSIL FORMED? Erosion Movement Sediment Layers Animal is buried by sediment Layers Minerals in rock layers replace the bones. Movement Movement of tectonic plates pushes the fossil closer to the surface. Erosion Erosion or people expose the preserved remains. 5

FIVE MAIN TYPES OF FOSSILS Petrified Fossils Molds and Casts Carbon Films Trace Fossils Preserved Remains 6

PETRIFIED FOSSILS The word “petrified” means “turning into stone.” PETRIFIED FOSSIL The Field Museum in Chicago displays a fossil of a Tyrannosaurus rex. The word “petrified” means “turning into stone.” Petrified fossils form when minerals replace all or part of an organism. 7

MOLDS AND CASTS MOLD FOSSIL This mold, or imprint, is of an extinct mollusk called an ammonite. A mold forms when hard parts of an organism are buried in sediment, such as sand, silt, or clay. The hard parts completely dissolve over time, leaving behind a hollow area with the organism’s shape. CAST FOSSIL This ammonite cast was discovered in the United Kingdom. 8

CARBON FILMS FERN FOSSIL This carbon-film fossil of a fern is more than 300 million years old. All living things contain an element called carbon. When an organism dies and is buried in sediment, the materials that make up the organism break down. Eventually, only carbon remains. The thin layer of carbon left behind can show an organism’s delicate parts, like leaves on a plant. 9

FANCY FOOTWORK This dinosaur footprint was found in Namibia, Africa. TRACE FOSSILS Trace fossils show the activities of organisms, like a footprint. FANCY FOOTWORK This dinosaur footprint was found in Namibia, Africa. 10

PRESERVED REMAINS Some organisms get preserved in or close to their original states. Here are some ways that can happen. Tar An organism, such as a mammoth, is trapped in a tar pit and dies. The tar soaks into its bones and stops the bones from decaying. Ice An organism, such as a woolly mammoth, dies in a very cold region. Its body is frozen in ice, which preserves the organism—even its hair! Amber An organism, such as an insect, is trapped in a tree’s sticky resin and dies. More resin covers it, sealing the insect inside. It hardens into amber. 11

COMPLETE the following activities on your worksheet... Video - Becoming a Fossil http://www.pbs.org/wgbh/nova/education/evolution/b ecoming-fossil.html Interactive - Geologic Time Scale http://www.alfmuseum.org/interactive1.htm http://science.nationalgeographic.com/science/prehistor ic-world/prehistoric-time-line/ Interactive - Digging in the Dirt http://www.nature.ca/discover/exf/dggngnthdrt/index_ e.cfm 12