Information about fossils: Geologic timescale

Here you can see the main events that occurred in the different geologic periods. The oldest period is at the bottom, because the oldest layers are also at the bottom. We now live in the Holocene, part of the Neogene period. The main classification is the "Era", the subdivisions are the "Periods". You can click on the fossilnames for more explanation.

ERA	PERIOD	Age (in millions of years)	Events:
Cenozoic	Neogene	0 - 23	The primates and humanoids developed in the upper Neogene.
Cenozoic	Paleogene	23 - 66	In the Paleogene period a fast development of mammals and birds occurred.
Mesozoic	Cretaceous	66 - 144	The dinosaurs became extinct at the end of the Cretaceous period almost certainly because of a large meteorite impact. Ammonites were flourishing during the Cretaceous, but they also became extinct. Mammals and flowering plants began developing.
	Jurassic	144 - 208	This is the time of the large reptiles. Many species of dinosaurs developed. Also flying dinosaurs, like the Archaeopteryx developed. These flying dinosaurs developed later into birds. The number of mammal species and crustaceans increased, and the first crocodiles appeared. The plants developed further. Many ammonites and sea urchins.
	Triassic	208 - 245	Beginning of the development of dinosaurs. First mammals and new species of plants appeared. This was the flourishing period of ferns. Fossils of turtles have been found.
Paleozoic	Permian	245 - 286	The final period of the Paleozoic. Further development of reptiles and many mollusks. First Ginkgo trees developed. The number of amphibians and insects decreased. The primitive armored fishes became extinct. Flourishing period of the Trilobites. At the end of the Permian there was an mass-extinction. The cause is still unclear.
	Carboniferous	286 - 360	First reptiles. Further development of flying insects, amphibians and plants. First sigularia trees. Extinction of the graptolites.
	Devonian	360 - 408	First sharks, amphibians, ammonites, and insects. The diverse group of crustaceans probably first left the water. Fishes left the water too. Large number of species of invertebrates and fishes. Development of plant leaves.
	Silurian	408 - 438	Many mollusks, gastropods, bryozoans, brachiopods and jawless fishes roamed the earth. First land plants and land animals.
	Ordovician	438 - 505	In the Ordovician period there were many trilobites and graptolites. Several mollusks developed. The number of species of primitive fishes and (sea)plants increased. Brown, red and green algae developed. First fishes with a developed skeleton and muscles. At the end of the Ordovician period there is a mass extinction.
	Cambrian	505 - 570	Cambrian explosion of life. Development of algae and animals with armor. In this period there were many species of trilobites, jellyfish, sponges, graptolites, echinoderms, brachiopods en inkfish. First primitive vertebrates, primitive fishes and (sea)plants (psilophytes).
Proterozoic	Precambrian	570 - 2.500	From the Archaeic (3800 to 2500) fossils are found of cyanobacteria in marine sediments. Stromatolites From the early an middle Proterozoic (2500 to 900) colonies of bacteria (without nucleus) are known followed by the first Eukaryotes (bacteria with a nucleus). From the late Proterozoic (900 to 570) the first colonies of sponges are known.
Archean		2.500 - 3.800
Hadean		3.800 - 4.600