300 Million Years Ago	Early Amphibians and Earthworms
2 Million Years Ago	First Humans Appear, Homo habilis; Modern Horse, Equus
160 Million Years Ago	Early Birds
410 Million Years Ago	Earliest Land Plants
450 Million Years Ago	First Fish
10 Million Years Ago	Mammoth Cave, KY, Begins to Form
510 Million Years Ago	First Marine Hard-Shell Animals
3 Billion Years Ago	Bacteria; First Signs of Life
65 Million Years Ago	Dinosaurs Are Extinct; Age of Mammals Begins
150 Million Years Ago	Early Mammals
290 Million Years Ago	First Reptiles
240 Million Years Ago	Start of Age of Dinosaurs
350 Million Years Ago	First Land Animals (Scorpions)
1.5 Million Years Ago	Ice Ages Begin
50 Million Years Ago	Modern Plants; First Known Horse, Hyracotherium
255 Million Years Ago	Early Insects
130 Million Years Ago	First Flowering Plants Develop
180 Million Years Ago	Bony Fish and Palm Trees
3.4 Billion Years	Oldest Known Fossil: Blue-Green Algae
140 Million Years Ago	Archaeopteryx
250 Million Years Ago	Greatest Extinction on Earth; 90% of Life
20,000 Years Ago	Men Began to Paint on Cave Walls
400 Million Years Ago	Sharks and Spiders
480 Million Years Ago	First Vertebrate
20 Million Years Ago	First Primate, Prosimian; Prehistoric deer and camels in N. America
230 Million Years Ago	Lizards Appear
550 Million Years Ago	Trilobites
600 Million Years Ago	Jellyfish
400,000 Years Ago	Discovery of Fire
350 Million Years Ago	Ferns
100,000 Years Ago	Mammoths
4,600 Million Years Ago	Earth Formed
70 Million Years Ago	Modern Birds and Snakes Develop
40 Million Years Ago	First Elephants
45,000 Years Ago	Homo sapiens sapiens
5,000 Years Ago	Development of Writing
200 Million Years Ago	World Land masses joined into one landmass called Pangaea