GeologyRocks

The second period of the Palaeozoic. Spans 510-443. The Ordovician is famous for its graptolite and trilobite-rich deposits, particularly in the UK. The Ordovician ended in a mass extinction, probably caused by an Ice Age.
Epochs:

• Upper: 460-443Ma
• Middle: 471-460Ma
• Lower: 488-471Ma

Which is split into:

• Hirnantian: 445-443Ma
• Stage 6: 455-445Ma
• Stage 5: 460-455Ma
• Darriwilian: 468-460Ma
• Stage 3: 471-468Ma
• Stage 2: 478-471Ma
• Tremadocian: 488-478Ma