| Era |
Period |
M.Y.B.P.
Millions of
years before present |
Event |
| Cenozoic |
Quaternary |
0-1.7 |
Humans. |
| Tertiary |
1.7-65 |
Modern
bivalves and gastropods
appear and radiate. Early mammals. |
| Mesozoic
|
Cretaceous |
65-135 |
Brachiopods decline. Radiation of
insect orders associated with flowering
plants. Ended in a mass extinction. |
| Jurassic |
135-192 |
Brachiopods, corals, and
marine bivalves common. South America and Africa
separate, and Atlantic Ocean is born. |
| Triassic |
192-230 |
Increase in
diversity of marine invertebrates. First flies and
sawflies. First dinosaurs. |
| Palaeozoic |
Permian |
230-280 |
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. |
| Carboniferous |
280-345 |
Insects colonise land. Giant
dragonflies. Corals and
brachiopods abundant. British climate is
equatorial. |
| Devonian |
345-405 |
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. |
| Silurian |
405-430 |
Bryozoans, corals and
brachiopods abundant. First evidence of
scorpions. Europe collides with N. America and
Greenland. |
| Ordovician |
430-500 |
Marine
invertebrates abundant. Trilobites declining. Spread of molluscs. Armoured fish. Earliest crustaceans. The Ordovician ended in a mass extinction. |
| Cambrian |
500-600 |
Origin of many
invertebrate phyla. Trilobites dominant. Small molluscs. Britian and Europe in the southern
hemisphere. |
| Precambrian |
600-4600 |
Animal fossil
evidence rare; evidence of sponges,
cnidaria, ctenophora,
and worm burrows c. 670-570 MYBP. Anaerobic bacteria about 3800
MYBP. |
![[]](http://m3.moostik.net/img/?pseudo=bumblebeepages&cpt=IGeological&option=invisible)