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Earth's Timeline

The Earth's crust, oceans and atmosphere have evolved over an enormous timescale. Geologists (scientists who study the earth) have broken this timescale up into a number of boxes that are usually represented by specific types of rocks or fossils.  Names have been given to each of these boxes; and increasingly accurate ages are given to their boundaries.

Some of the boxes are named after places where the rocks were studied in detail (eg the Devonian after Devon).  Because the world's surface plates are constantly moving, albeit very slowly, the rocks vary at different times.  For example the Devonian sandstones of England represent a time when southern England was in the southern latitudes, near the area occupied by the Namibian deserts today.  The Carboniferous rocks in England include coals deposited by vast forests when England lay on the Equator, and the Permian sandstones when we were at the latitude of the western Sahara.  During the Jurassic we were crossing the latitude of the Mediterranean and moving north through where Spain is now.  During the Cretaceous and Palaeogene we were moving through northern Spain and modern France to our current position. Our northward movement has now slowed right down and we have changed direction - moving eastwards, while North America is moving to the west.

We have included information on this webpage which describes the overall scheme and where the Isle of Wight fits into the global timescale. The time zones have been put into table form so that we can update them as more accurate techniques and data become available. Some significant events for life have also been added - the times of arrival of whole new groups of organism, and the timing of major extinctions.

The stratigraphic dates below were published in February 2014 by the International Commission on Stratigraphy.

Stratigraphic table and dates

Eon: Phanerozic - 542 million years to the present

Era:	Period:	Starting age
Caenozoic	Quaternary	2.58 Ma
	Neogene	23.03 Ma
	Palaeogene	66.0 Ma
Mesozoic	Cretaceous	~145.0 Ma
	Jurassic	201.3 +/- 0.2 Ma
	Triassic	252.17 +/- 0.06 Ma
Palaeozoic	Permian	298.9 +/- 0.15 Ma
	Carboniferous	358.9 +/- 0.4 Ma
	Devonian	419.2 +/- 3.2 Ma
	Silurian	443.4 +/- 1.5 Ma
	Ordovician	485.4 +/- 1.9 Ma
	Cambrian	541.0 +/- 1.0 Ma

Eon: Proterozoic - 2500 million years to 542 million years

Era:	Period:	Starting age
Neoproterozoic	Ediacaran	~635 Ma
	Cryogenian	850 Ma
	Tonian	1000 Ma
Mesoproterozoic	Stenian	1200 Ma
	Ectasian	1400 Ma
	Calymmian	1600 Ma
Palaeoproterozoic	Statherian	1800 Ma
	Orosirian	2050 Ma
	Rhyacian	2300 Ma
	Siderian	2500 Ma

Eon: Archaen - 4000 million years to 2500 million years

Era:	Period:	Starting age
Neoarchean		2800 Ma
Mesoarchean		3200 Ma
Palaeoarchaen		3600 Ma
Eoarchaen		4000 Ma

Eon: Hadean (informal)  - 4600 million years to 4000 million years

Era:	Period:	Starting age
To be determined		~4600 Ma

Dates published in 2014 by the International Commission on Stratigraphy.
(Ma = Mega annum - 'million years' ago).
The Proterozoic and Archaean are sometimes referred together as the 'Precambrian'.

Approximate first appearance of new types of organism

Organism	Time zone	approx date
Grasses	Oligocene	30 Ma
Bees	Cretaceous	100 Ma
Flowering plants	Cretaceous	135 Ma
Bird-type dinosaurs	Late Jurassic	150 Ma
Mammals	Triassic	220 Ma
Dinosaurs	Triassic	228 Ma
Ferns	Carboniferous	300 Ma
Conifers	Carboniferous	300 Ma
Reptiles	Carboniferous	310 Ma
Land vertebrates	Devonian	380 Ma
Insects	Devonian	400 Ma
Vertebrates with jaws	Devonian	410 Ma
Land plants, Fungi	Silurian	450 Ma
Jawless vertebrates	Ordovician	470 Ma
Crustaceans	Cambrian	530 Ma
Molluscs	Cambrian	530 Ma
Worms	Cambrian	540 Ma
Echinoderms (starfish etc), Sponges and Coelenterates (jellyfish etc)	Cambrian	540 Ma
Unicellular animals	Neoproterozoic	700 Ma
Algae	Palaeoproterozoic	2,100 Ma
Bacteria	Palaeoarchaen	3,600 Ma

Extinctions

Organism	Type	Time zone	Approx date
Dodo	Flightless bird	Holocene	Last survivor reported 1681
Dwarf mammoth (Wrangel Island, Russian arctic)	Large mammal	Holocene	6,360 years ago
Mammoth (N. America)	Large mammal	Holocene	10,000 years ago
Ammonoids	Marine animal	End Cretaceous	65 Ma
Belemnites	Marine animal	End Cretaceous	65 Ma
Dinosaurs	Land animal	End Cretaceous	65 Ma
Rudist & Trigoniid bivalves	Marine mollusc	End Cretaceous	65 Ma
Plesiosaurs	Marine reptile	End Cretaceous	65 Ma
Pterosaurs	Flying reptile	End Cretaceous	65 Ma
Hybodont sharks	Marine animal	End Cretaceous	65 Ma
Ichthyosaurs	'fish lizard' - marine reptile	Upper Cretaceous	95 Ma
Trilobites	Marine animal	Permian
Placodermia	Armoured fish	End Carboniferous
Ancient ferns	Land plant	Upper Carboniferous
Graptolites	Marine animal	Upper Carboniferous

Rocks and fossils of the Isle of Wight

Era:	Period:	Epoch:	Rock Groups:	Approx age	Typical fossils
Caenozoic	Quaternary	Pleistocene		?	Bison, elephant
	Palaeogene	Oligocene	Solent	34-33 Ma	Plants, Birds
		Eocene	Solent	38-34 Ma	Molluscs, mammals
		Eocene	Barton	-38 Ma	Molluscs
		Eocene	Bracklesham	51-	Molluscs
		Eocene	Thames	54-51 Ma	Shark teeth, molluscs
		Palaeocene	Lambeth	56-55 Ma
Mesozoic	Cretaceous (K)	Upper K	White Chalk	93.5-68 Ma	Ammonites, belemnites, sea-urchins, shark teeth, sponges
		Upper K	Grey Chalk	99-93.5 Ma	Ammonites, sea-urchins, sponges
		Lower K	Upper Greensand	105-99 Ma	Ammonites, sponges, sharks, molluscs
		Lower K	Lower Greensand	120-	Ammonites, lobsters, oysters
		Lower K	Wealden	126-120 Ma	Dinosaur bone and footprints!, crocodile, fish, turtle, pterosaur, bivalves, gastropods, ostracods