20. Deepest Gratitude to Image Sources http://www.oursaviorchurch.org/school/faculty/gthorp/wp-content/uploads/2007/05/tour_grand_canyon_1.jpg http://www.exw6sxq.com/sparky/images/anticline_and_syncline.jpg http://earth.boisestate.edu/home/cjnorth/images/deformed_pillowbas.jpg http://www.geobabble.org/~hnw/vendian.jpg http://www.palaeos.com/Proterozoic/Neoproterozoic/Ediacaran/Images/Microdictyon.jpg http://palaeo.gly.bris.ac.uk/Palaeofiles/Taph/Report2/Ediacaran.gif http://www.celestiamotherlode.net/catalog/images/screenshots/various/fictional_Snowball_Earth_1__Neethis.jpg http://nai.nasa.gov/newsletter/03182005/snowball.jpg http://photo.agiweb.org/utils/showimage.php?ID=hpdsw9 http://www.geology.wisc.edu/~g109/images/Life/L5_Ordovician_Life_More.jpg http://www.tolweb.org/tree/ToLimages/Hudsonaster.jpg http://www.bizleyart.com/Root%20folder/Prehistoric/0534-Silurian%20lg.jpg http://higheredbcs.wiley.com/legacy/college/levin/0471697435/chap_tut/images/nw0213-nn.jpg http://www.uky.edu/KGS/fossils/images/devosea.jpg http://www.emc.maricopa.edu/faculty/farabee/BIOBK/aLate_Dev.jpg http://www-tc.pbs.org/wgbh/nova/link/images/hist_img_06_carb.jpg?Log=0 http://www.amnh.org/learn/courses/images/sharks11.jpg http://palaeo.gly.bris.ac.uk/essays/lystrosaurus.jpg http://www.lpi.usra.edu/education/timeline/gallery/images/053.jpg http://prehistoricsillustrated.com/images_kc/th_triassic_scene.jpg http://uktv.co.uk/images/standarditem/L1/574844_L1.jpg http://universe-review.ca/I10-68-Jurassic.jpg http://www.brixworth.demon.co.uk/dino.jpg http://www.eere.energy.gov/buildings/highperformance/zion/images/geology_photo.jpg http://www.handprint.com/PS/GEO/cenoq.jpg http://www.pibburns.com/cryptost/arg-01.jpg http://www.geus.dk/geus-general/geus-facts/fak02-presse-foto07.jpg http://www.fossilbeds.org/wp-content/uploads/2007/06/cvsandhwm.jpg http://www.crystalinks.com/crystalsmexico.jpg http://www.canyonsworldwide.com/crystals/pictures/CrystalCavesRick.jpg