Appendix:Geologic timescale

The eons, eras, periods and epochs of geologic time - most recent first - numbers are millions of years ago and mark the end of the timeframe

Phanerozoic eon

Cenozoic era

66-present

Quaternary period

• 2.58-present

Holocene epoch

• 0.0117-present - end of most recent glaciation; start of civilization

Pleistocene epoch

• 2.58-0.0117 - rise and fall of the large mammals, evolution of man

Upper Pleistocene age

• 0.126-0.0117

Middle Pleistocene age

• 0.781-0.126

Calabrian age

• 1.80-0.781

Gelasian age

• 2.58-1.80

Neogene period

• 23.03-2.58

Pliocene epoch

• 5.333-2.58 - ice age, modern mammals and molluscs appear

Piacenzian age

• 3.600-2.58

Zanclean age

• 5.333-3.600

Miocene epoch

• 23.03-5.333 - moderate climate, mountain building, modern mammals & birds appear, grasslands expand

Messinian age

• 7.246-5.333

Tortonian age

• 11.62-7.246

Serravallian age

• 13.82-11.62

Langhian age

• 15.97-13.82

Burdigalian age

• 20.44-15.97

Aquitanian age

• 23.03-20.44

Paleogene period

• 66.0 - 23.03 - Mild change in climate, spread of mammals and birds.

Oligocene epoch

• 23 - warm climate, rapid evolution,

Eocene epoch

• 34 - archaic mammals, start of current ice age

Paleocene epoch

• 56 - tropical climate, first large mammals

Mesozoic era

• Reign of reptiles (Dinosaurs)

Cretaceous period

Upper epoch

• 66 - Last dinosaurs

Lower epoch

• 100 - break up of Gondwanaland, flowering plants and Bees

Jurassic period

• 201.3-145.0 - Peak of reptiles, first birds and true mammals

Upper epoch

• 145 - Peak of sauropods

Middle epoch

• 161 - lizards, mammals

Lower epoch

• 175 - ammonites

Triassic period

Upper epoch

• 200 -- archosaurs

Middle epoch

• 230 - amphibians, First dinosaurs

Lower epoch

• 245 - first small mammals

Paleozoic era

Permian period

Lopingian epoch

• 251 - supercontinent of Pangea

Guadalupian epoch

• 260 - gymnosperms

Cisuralian epoch

• 270 - beetles and flies

Carboniferous period

Upper Pennsylvanian epoch

• 299 - winged insects

Middle Pennsylvanian epoch

• 306 - reptiles, coal forests

Lower Pennsylvanian epoch

• 312 - high oxygen content atmosphere

Upper Mississippian epoch

• 318 - primitive trees

Middle Mississippian epoch

• 326 - primitive sharks

Lower Mississippian epoch

• 345 - glaciation

Devonian period

Upper epoch

• 359 - clubmosses

Middle epoch

• 385 - crinoids

Lower epoch

• 398 - jawed fish

Silurian period

Pridoli epoch

• 416 - first vascular land plants

Ludlow epoch

• 419 - millipedes

Wenlock epoch

• 423 - corals

Llandovery epoch

• 428 - trilobites

Ordovician period

Upper epoch

• 443 - invertebrates dominant

Middle epoch

• 461 - starfish

Lower epoch

• 471 - first land plants

Cambrian period

• 541.0±1.0-485.4±1.0

Furongian epoch

• 497-485.4±1.0

Stage 10

• 489.5-485.4±1.0 - Cambrian explosion of life

Jiangshanian

• 494-489.5

Paibian

• 497-494 - Trilobites

Series 3

• 509-497

Guzhangian

• 500.5-497

Drumian

• 504.5-500.5

Stage 5

• 509-504.5

Series 2

• 521-509

Stage 4

• 514-509 - sponges

Stage 3

• 521-514

Terreneuvian

• 541.0±1.0-521

Stage 2

• 529-521

Fortunian

• 541.0±1.0-529

Proterozoic eon

2,500-541.0±1.0

Neoproterozoic era

1,000-541.0±1.0

Ediacaran period

• 635-541.0±1.0 - first multi-celled animals

Cryogenian period

• 850-635 - snowball earth

Tonian period

• 1,000-850 - acritarch radiation

Mesoproterozoic era

1,600-1,000

Stennian period

• 1,200-1,000 - formation of Rodinia

Ectasian period

• 1,400-1,200

Calymmian period

• 1,600-1,400

Paleoproterozoic era

2,500-1,600

Statherian period

• 1,800-1,600 - first complex single-celled life

Orosirian period

• 2,050-1,800 - transition to oxygen atmosphere

Rhyacian period

• 2,300-2,050

Siderian period

• 2,500-2,300

Archaean eon

4,000-2,500

Neoarchean era

2,800-2,500 - stabilization of most modern cratons

Mesoarchean era

3,200-2,800 - first stromatolites

Paleoarchean era

3,600-3,200 - first known aerobic bacteria

Eoarchean era

4,000-3,600 - first single-celled organisms

Hadean eon

Before 4,000

• ~4,000 - oldest known rock
• 4,400 - oldest known mineral
• 4,570 - Earth formed