what the graphics mean

Below are descriptions of all the graphics on the timeline. Organisms that point left are extinct.

To see the timeline and temperature record, CLICK HERE
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Otherwise start your journey...
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Cambrian Explosion (541 MYA)
​https://en.wikipedia.org/wiki/Cambrian_explosion

Trilobite (521 MYA)
https://en.wikipedia.org/wiki/Trilobite

Nautilus
(500 MYA)
https://en.wikipedia.org/wiki/Nautilus
Living fossil

Ice Age (450-420 MYA)
https://en.wikipedia.org/wiki/Andean-Saharan_glaciation

Ordovician Silurian Extinction (450 MYA)
https://en.wikipedia.org/wiki/Ordovician%E2%80%93Silurian_extinction_events

Land Plants (425 MYA^)
https://en.wikipedia.org/wiki/Embryophyte

Coelacanth (400 MYA)
​​https://www.thoughtco.com/coelacanths-worlds-only-living-extinct-fish-1093326
​Living fossil

Lungfish (400 MYA)
​​https://en.wikipedia.org/wiki/Lungfish
​Living fossil

Acanthostega, First Land Vertebrates (365 MYA^)
​https://www.thoughtco.com/tetrapods-the-fish-out-of-water-1093319
Tiktaalik may have been the first to venture onto land.

Late Devonian Extinction (375 MYA)
https://en.wikipedia.org/wiki/Late_Devonian_extinction

Ice Age (360-260 MYA)
https://en.wikipedia.org/wiki/Late_Paleozoic_icehouse

First Reptiles (315 MYA^)
https://en.wikipedia.org/wiki/Reptile#Evolutionary_history

Dimetrodon (295-272 MYA)
​https://www.thoughtco.com/reptiles-that-ruled-earth-before-dinosaurs-1093310
​More closely related to humans than Dinosaurs.

Permian–Triassic Extinction (252 MYA)
https://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event

Pangea (335-175 MYA)
​​https://en.wikipedia.org/wiki/Pangaea
​https://deeptimemaps.com/
​https://dinosaurpictures.org/ancient-earth/view/Euoplocephalus#200

First Dinosaurs (240 MYA^)
https://en.wikipedia.org/wiki/Dinosaur​

First Mammals (225 MYA^)
https://en.wikipedia.org/wiki/Mammal#First_mammals

Triassic–Jurassic Extinction (201 MYA)
https://en.wikipedia.org/wiki/Triassic%E2%80%93Jurassic_extinction_event

Flowers (200-130 MYA^)
​https://en.wikipedia.org/wiki/Evolutionary_history_of_plants#Flowers

Stegosaurus (150 MYA)
​https://en.wikipedia.org/wiki/Stegosaurus
Extinct 80 million years before the first T-Rex appeared.

Crocodilia (95 MYA^)
https://en.wikipedia.org/wiki/Crocodilia
​Living Fossil

North America Developing (75 MYA^)
​https://deeptimemaps.com/

Cretaceous-Paleogene Extinction (66 MYA)
https://www.nationalgeographic.com/science/prehistoric-world/dinosaur-extinction/

6-9 mile asteroid or comet killed all endothermic Tetrapods over 55 pounds plus all non-avian Dinosaurs
https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event

Cynodonts & Cenozoic Era (66 MYA-)
​https://www.thoughtco.com/the-cenozoic-era-1091364
https://en.wikipedia.org/wiki/Cynodont

Long Term Climate Variations in the US (B=50 MYA)
https://dinosaurpictures.org/ancient-earth/view/Euoplocephalus#50
(A=13 KYA)​​https://en.wikipedia.org/wiki/Last_Glacial_Maximum

Pelicans (30 MYA^)
https://en.wikipedia.org/wiki/Pelican
​Living Fossil

First Hominids (20 MYA^)
https://en.wikipedia.org/wiki/Hominidae

Bipedalism (12-5 MYA^)
https://en.wikipedia.org/wiki/Bipedalism#Evolution_of_human_bipedalism​

North America Developing (5 MYA^)
​https://deeptimemaps.com/

Australopithecus (4.2 MYA^)
​https://en.wikipedia.org/wiki/Australopithecus

Lucy (3.2 MYA)
​https://en.wikipedia.org/wiki/Lucy_(Australopithecus)

Stone Age, Hand Tools (3.2 MYA)
https://en.wikipedia.org/wiki/Stone_Age
https://en.wikipedia.org/wiki/Stone_tool​

Current Ice Age started (2.6 MYA)
https://en.wikipedia.org/wiki/Quaternary_glaciation

Milankovitch Cycles (2.5 MYA to present)
​https://en.wikipedia.org/wiki/Milankovitch_cycles

Out of Africa I (2 MYA^)
https://en.wikipedia.org/wiki/Early_expansions_of_hominins_out_of_Africa​

Using Fire (2-1 MYA^)
https://en.wikipedia.org/wiki/Control_of_fire_by_early_humans

First Boats or "Dugouts" (900 KYA^)
​https://en.wikipedia.org/wiki/Boat#History

Clothing (500-100 KYA^)
https://en.wikipedia.org/wiki/History_of_clothing_and_textiles#Prehistoric_development

First Homo Sapiens (300 KYA^)
https://en.wikipedia.org/wiki/Human

Cooking Hearths (300 KYA^)
https://en.wikipedia.org/wiki/Cooking#History

Out of Africa II (250 KYA^)
https://en.wikipedia.org/wiki/Recent_African_origin_of_modern_humans

"Modern" Humans (200-100 KYA^)
https://en.wikipedia.org/wiki/Early_modern_human

First Jewelry (100 KYA^)
​https://en.wikipedia.org/wiki/Jewellery

Harpoon (90 KYA^)
​https://en.wikipedia.org/wiki/Harpoon#History

First Known Drawing (100-70 KYA^)
​https://www.history.com/news/prehistoric-hashtag-stone-age-painting

Toba Super Volcano (75 KYA)
https://en.wikipedia.org/wiki/Toba_catastrophe_theory

Pressure Flaking (70 KYA^)
​https://en.wikipedia.org/wiki/Lithic_reduction#Pressure_flaking

Bow & Arrow (64 KYA^)
https://en.wikipedia.org/wiki/History_of_archery#Prehistory

First Bone Sewing Needle (60 KYA^)
​https://en.wikipedia.org/wiki/Sewing_needle#History

Cave Painting, Cave Art (40 KYA^)
​https://en.wikipedia.org/wiki/Cave_painting

Music (40+ KYA^)
https://en.wikipedia.org/wiki/Music#History

Dogs Domesticated (30 KYA^)
​https://en.wikipedia.org/wiki/Dog#Roles_with_humans

Neanderthals Extinct (30 KYA^)
https://en.wikipedia.org/wiki/Neanderthal

Venus of Willendorf (25 KYA^)
​https://en.wikipedia.org/wiki/Venus_of_Willendorf

First Fishing Hooks (23 KYA^)
​https://en.wikipedia.org/wiki/Fish_hook#History

Beringia (21-11 KYA)
https://en.wikipedia.org/wiki/Beringia 
North American ancestors came via Russia/ Alaska

Younger Dryas (13 KYA)
​https://en.wikipedia.org/wiki/Younger_Dryas 
Possibly caused by comet

End of Last Glacial Period (12 KYA)
https://en.wikipedia.org/wiki/Last_Glacial_Period

Gobekli Tepe (11 KYA^)
https://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe
Agriculture (12 KYA^)
https://en.wikipedia.org/wiki/Agriculture#History
Jericho (12 KYA^)
https://en.wikipedia.org/wiki/Jericho#Stone_Age:_Tell_es-Sultan_and_its_spring

Cats Domesticated (10-8 KYA^)
https://en.wikipedia.org/wiki/Evolution_of_the_domesticated_cat

The Wheel (6 KYA^)
https://en.wikipedia.org/wiki/Wheel#History

First Sail Boats (6-4 KYA^)
https://en.wikipedia.org/wiki/Sail#History

Earliest Salt Use (6-4 KYA^)
https://seasalt.com/history-of-salt

Bronze Age (3000 BCE^)
https://en.wikipedia.org/wiki/Bronze_Age

Cuneiform (3000 BCE^)
https://en.wikipedia.org/wiki/Cuneiform

Horses Domesticated (3000 BCE^)
https://en.wikipedia.org/wiki/Domestication_of_the_horse

​Khufu / Cheops / Great Pyramid (2560 BCE^)
https://en.wikipedia.org/wiki/Great_Pyramid_of_Giza 

Pythagorean Equation (2000 BCE - 570 BCE)
https://en.wikipedia.org/wiki/Pythagorean_theorem#History

Iron Age, Huts (1200 BCE^)
https://en.wikipedia.org/wiki/Roundhouse_(dwelling)#United_Kingdom
https://en.wikipedia.org/wiki/Iron_Age

First Olympic Games (776 BCE)
https://en.wikipedia.org/wiki/Ancient_Olympic_Games

Parthenon (438 BCE)
https://en.wikipedia.org/wiki/Parthenon

Plato's Republic (375 BCE)
https://en.wikipedia.org/wiki/Republic_(Plato)

Rosetta Stone (196 BCE)
https://en.wikipedia.org/wiki/Rosetta_Stone

Roman Empire starts (27 BCE)
https://en.wikipedia.org/wiki/Roman_Empire

Gunpowder (800)
https://en.wikipedia.org/wiki/History_of_gunpowder

First University (1088)
https://en.wikipedia.org/wiki/University_of_Bologna

Renaissance (15th-16th Centuries^)
https://en.wikipedia.org/wiki/Renaissance

The Sistine Chapel Ceiling (1508)
https://en.wikipedia.org/wiki/Sistine_Chapel_ceiling

"Little Ice Age" (1400s - 1800s)
https://en.wikipedia.org/wiki/Little_Ice_Age

Printing Press (1440)
https://en.wikipedia.org/wiki/Printing_press

Industrial Revolution (1750)
​https://en.wikipedia.org/wiki/Industrial_Revolution

Power Loom (1787)
https://en.wikipedia.org/wiki/Power_loom

Lighting (1883)
https://en.wikipedia.org/wiki/Incandescent_light_bulb#History

Ford Model T (1908)
https://en.wikipedia.org/wiki/Ford_Model_T