Dinosaur Discoveries: Unveiling Earth's Prehistoric Secrets

1. Today – 1/23 • Critter in the news • Reading background • History of dinosaur discoveries

3. ScienceDaily.com

4. P-T extinction • Before: simple and complex marine ecosystems exist in equal numbers • After: complex marine ecosystems outnumber simple ones 3 to 1 • Discovered because of the web and a new analytical approach

5. 3-point XC opportunity • Tonight, 7:30 pm, Kuiper Space Sciences 308 • Surface of Titan, a moon of Saturn • Check in with me before • Sit with me or 1-page summary

6. Admistration • First short writing assignment comments • Pick up papers in G-S 205 • Posting grades

7. Last time: • River types – meandering vs. braided • Carbon isotopes • K-T impact • P-T scenario

9. 3500 K 4800 K 5500 K

10. The Geodynamo

11. Mid-Ocean Ridges (MOR’s)

12. Magnetic Striping of the Sea Floor

13. MORs and Magnetic Striping www2.nature.nps.gov/geology/usgsnps/animate

14. Magnetic striping of the seafloor • Convecting liquid outer core generates Earth’s magnetic field • Heat from the core and radioactive decay drives mantle convection and plate tectonics making new rocks at mid-ocean ridges • New rocks record polarity of Earth’s magnetic field!

15. Iceland

16. Magnetostratigraphy • Drill a bunch of cores going up through layers • Analyze them to determine the pattern of magnetic polarity through time • Match them (like tree rings) to the appropriate part of the known pattern for Earth throughout time, read off the date

17. Insert pic of AC • Petrified tree? • AC shot from above! With inset of teeth

18. What fossils tell us about dinosaurs • How they looked - size, shape, skin • How they behaved - diet, locomotion, social life, as parents • Physiology - thermal regulation, growth patterns • History of life - speciation and extinction, relationships among groups • Environmental reconstruction, rock ages geochemistry, paleogeography, interaction between physical and biological worlds

19. ← Griffin inspired by Protoceratops? ↓ web.ukonline.co.uk/conker/ www.dinoland.dk

20. www.oum.ox.ac.uk/geolcoll.htm 1677 – Robert Plot publishes first known description of a dinosaur bone. However, he mistakes it for the femur of a giant human!

21. www.lhl.lib.mo.us/events_exhib/exhibit/ex_paper_dino.shtml 1815 – William Buckland finds Megalosaurus jaw

22. 1831 1830’s – Meet Meg, plus the happy water lizard home.uchicago.edu/~shburch/dinopaper.html 1833

23. 1836 – Gideon Mantell discovers the teeth of Iguanodon www.lhl.lib.mo.us/events_exhib/exhibit/ex_paper_dino.shtml

24. Iguanodon – notice the sprawling legs 1842 – Richard Owen defines the “Dinosauria”, which translates as “terrible lizards”

25. Depiction by Owen circa 1850

26. Benjamin Waterhouse Hawkins’ 1853 dinosaur reconstructions being prepared for display in the Crystal Palace, Hyde Park, London http://www.ric.edu/rpotter/cryspal.html

27. www.simondevlin.com

28. Importance of Hawkins • First attempt at full-scale reconstruction • Super-popularized dinosaurs • Cemented wrong views!

29. www.owen.k12.ky.us/trt/beverly/Megalosaurus_files/frame.htm

30. http://www.healthstones.com/dinosaurdata/dinodata.html

31. Nicholas Steno – “Father of stratigraphy” • Second half of the 1600’s • Said fossils were remains of organisms • Principle of Original Horizontality – rock layers laid down horizontally, any deviation from this due to later disturbance • Law of Superposition – lower layers are older, upper layers are more recent

32. Early 1800’s geology comes alive! • 1795 – Theory of the Earth by James Hutton: how rock layers form, hot inside, old, uniformitarianism, natural selection • 1815 – Geologic map by William Smith: biostratigraphy • 1830-1833 – Principles of Geology by Charles Lyell: stratigraphy • 1859: On the Origin of Species by Darwin