Geological table

M.Y.B.P.
Millions of years before present
Event
0-1.7 Quaternary
Humans.
1.7-65 Tertiary
Modern bivalves and gastropods appear and radiate. Early mammals.
65-135 Cretaceous
Brachiopods decline. Radiation of insect orders associated with flowering plants. Ended in a mass extinction.
135-192 Jurassic
Brachiopods, corals, and marine bivalves common. South America and Africa separate, and Atlantic Ocean is born.
192-230 Triassic
Increase in diversity of marine invertebrates. First flies and sawflies. First dinosaurs.
230-280 Permian
Insect diversification on land and in freshwater, first records of beetles. All continents joined together to form a single landmass. Ended with a mass extinction of 90% marine invertebrates, especially those living in shallow waters, all Trilobites became extinct, and 75% of land species became extinct.
280-345 Carboniferous
Insects colonise land. Giant dragonflies. Corals and brachiopods abundant. British climate is equatorial.
345-405

Devonian
The first record of insects, spiders and mites. Bryozoans and corals abundant. Great Glen and Highland boundary faults formed in what is now Scotland. Ended with a mass extinction which appears to have caused the extinction of 70% of animal species.

405-430 Silurian
Bryozoans, corals and brachiopods abundant. First evidence of scorpions. Europe collides with N. America and Greenland.
430-500 Ordovician
Marine invertebrates abundant. Trilobites declining. Spread of molluscs. Armoured fish. The Ordovician ended in a mass extinction.
500-600 Cambrian
Origin of many invertebrate phyla. Trilobites dominant. Earliest crustaceans. Small molluscs. Britain and Europe in the southern hemisphere.
600-4600 Precambrian
Animal fossil evidence rare; evidence of sponges, cnidaria, ctenophora, and worm burrows c. 670-570 MYBP. Anaerobic bacteria about 3800 MYBP.