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

ScienceDaily.com

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 approachweb

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

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

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

5500 K 4800 K 3500 K

The Geodynamo

Mid-Ocean Ridges (MOR’s)

Magnetic Striping of the Sea Floor

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

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!

Iceland

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

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

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

web.ukonline.co.uk/conker/ ← Griffin inspired by Protoceratops? ↓

– Robert Plot publishes first known description of a dinosaur bone. However, he mistakes it for the femur of a giant human!

– William Buckland finds Megalosaurus jaw

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

1836 – Gideon Mantell discovers the teeth of Iguanodon

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

Depiction by Owen circa 1850

Benjamin Waterhouse Hawkins’ 1853 dinosaur reconstructions being prepared for display in the Crystal Palace, Hyde Park, London

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

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

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 – Principles of Geology by Charles Lyell: stratigraphy 1859: On the Origin of Species by Darwin