years before present
bivalves and gastropods
appear and radiate. Early mammals.
||Brachiopods decline. Radiation of
insect orders associated with flowering
plants. Ended in a mass extinction.
||Brachiopods, corals, and
marine bivalves common. South America and Africa
separate, and Atlantic Ocean is born.
diversity of marine invertebrates. First flies and
sawflies. First dinosaurs.
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.
||Insects colonise land. Giant
dragonflies. Corals and
brachiopods abundant. British climate is
||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.
||Bryozoans, corals and
brachiopods abundant. First evidence of
scorpions. Europe collides with N. America and
invertebrates abundant. Trilobites declining. Spread of molluscs. Armoured fish. Earliest crustaceans. The Ordovician ended in a mass extinction.
||Origin of many
invertebrate phyla. Trilobites dominant. Small molluscs. Britian and Europe in the southern
evidence rare; evidence of sponges,
and worm burrows c. 670-570 MYBP. Anaerobic bacteria about 3800