Third of the six Paleozoic periods.
Began 444 mya and ended 416 mya, bracketed by extinction events.
Named after a Celtic tribe in south Wales, where the rocks were first studied.
Notable for immense coral reefs, the rapid evolution of jawless fishes, and the first good evidence of life on land.
There was one large continent, Gondwana, and two smaller ones, Euramerica and Siberia.
Image courtesy of Wikipedia.