Absolute Dating Chapter 3, section 3 Any method for finding the age of an event or object in years p. 70 1. What is the Difference between Relative dating and Absolute dating? Explain! Relative dating will give you an Approximate time frame or frame of reference (Is one object younger or Older than the other object?). Absolute dating determines how long something has existed.

For the purposes of studying how Radiometric Dating p.71 + 72 For the purposes of studying how old rock are, scientists examine how long it takes different types of radio-active isotopes (atoms) to break down. This radioactivity is used to determine the age of objects.

According to The American Institute of Biological Sciences: 2. If an object is 65 million years of age (Cretaceous), how accurate (within how many years) do you think radiometric Dating can be? Take a guess. According to The American Institute of Biological Sciences: It (radiometric dating) is accurate to within a few thousand years. With modern, extremely precise, methods, error bars are often only1% or so. © 2001, American Institute of Biological Sciences. Educators have permission to reprint articles for classroom use About the author: Michael Benton, Ph.D., is a vertebrate paleontologist with particular interests in dinosaur origins and fossil history. Currently, he is studying certain basal dinosaurs from the Late Triassic and the quality of different segments of the fossil record. He holds the Chair in Vertebrate Paleontology at the University of Bristol, UK, in addition to chairing the Masters program in paleobiology at the university. He has written some 30 books on dinosaurs and paleobiology, ranging from professional tomes to popular kids' books. http://www.gly.bris.ac.uk/www/admin/personnel/MJB.html

We are moving ahead………….. B gg We are moving ahead………….. “Looking at fossils” p. 74 Chapter 3 Section 4

The remains or physical evidence of an organism Fossil p. 74 The remains or physical evidence of an organism preserved by geologic processes. 3.Why are insects preserved so well in amber? Explain: 4.What type of rock will you find fossils? Why?

Petrified wood 5. What is Permineralization ? 6. What do these two specimens have in common? page 75 Petrified Dinosaur Skull and jaw bone Petrified wood

7. Explain why we have found the Remains of woolly mammoths La Brea Tar Pits p. 75 7. Explain why we have found the Remains of woolly mammoths in the La Brea Tar Pits

Baby mammoth undergoes tests By Doug O'Harra Frozen Fossils p. 76 July 25th, 2007 at 4:00 am (posted)

The frozen, nearly intact remains of a 4-month-old female wooly mammoth.

Frozen fossils p. 75 p. 75 The well-preserved remains of a four-month-old baby wooly mammoth recovered from melting permafrost in Siberia last spring will now undergo sophisticated testing and analysis at University of Michigan. U-M paleontologist Daniel Fisher on the left, U-M graduate student Adam Rountrey in the middle and Alexei Tikhonov at right.

Tissue decay is slowed down 8. Why are animals preserved so Well in the Siberian Tundra? P. 75 Tissue decay is slowed down Due to the extreme cold temperatures

9. What is a trace fossil? P. 76 Theropod dinosaur track A fossilized mark that is formed in soft sediment by the movement of an animal

What animal Made the tracks visible in this picture? Tracks of a polar bear in the fine-grained sediments of an alluvial plain may become trace fossils one day.

a sedimentary surface by 11. Define: Mold fossil A mark or cavity made in a sedimentary surface by a shell or other body

Cast fossil A type of fossil that forms when Sediments fill in the cavity left By a decomposed organism.

Define: Cast fossil p. 76 Cast fossil A reconstruction of Tiktaalik alongside a cast of its fossil, and a map showing where the fossil was found, on Ellesmere Island, Nunavut, Canada. Define: Cast fossil p. 76 Cast fossil

formed when a mold is filled in Type of Fossil How the Fossil Was Formed Picture Example Mold Fossil a fossilized impression made in the substrate - a negative image of the organism                      Cast Fossil formed when a mold is filled in Trace Fossil fossilized nests, gastroliths, burrows, footprints, etc                                                      

Mold p. 76 Cast Dr. Farley Fleming, a USGS fossil pollen specialist helped to establish the relative age and stratigraphic position of the track layer. He determined that the track was probably made 65-70 million years ago Pictured below is a fossilized track of the hind foot of a large dinosaur. The track was discovered in northeastern New Mexico in 1983 by Charles Pillmore, a research geologist with the U.S. Geological Survey in Denver, CO. The track only recently was identified as a footprint made by a Tyrannosaurus rex, and presently is recognized as the only known fossilized track made by this creature. Although several nearly complete fossil skeletons of the large dinosaur have been found, until 1993 no tracks attributable to this creature had been reported.

“Quick Lab” Make a fossil Find a common objects, such as shells, a buttons, or a pencils, etc.. to use to make molds. (10) Keep the object hidden from the other groups. Press the items into the play doh to create the mold. (your group should end up with a tray of 10 different molds. 3. Trade your tray of 10 with another group. Use the activity sheet to record your data. Answer the questions from the data sheet. p. 77

Information from fossils p. 77 Why do scientists know more about ancient Animals that have hard body parts than those with soft body parts? What are 2 reasons for the Fossil record being incomplete?

13.What types of information Can scientists gather from Fossil records? P. 77 Tropite Plant Fossil

14)What is an index fossil. P. 78 A fossil that is found in the rock layers of only one geologic age and that is used to establish the age of the rock layers There were many different species of ammonite living in all oceans, and each species was quite short-lived, so now paleontologists use ammonites as 'index' fossils, helping to define the age of a fossil bed.

Trilobite Approximately 400,000,000 years old Index fossil which Lived….. Approximately 400,000,000 years old

Section Review Ch. 3 section 4 You are to use your notes from this power point presentation and your “Mold fossil Lab” to study for your quiz tomorrow. Section Quiz Date: February 6, 2008