Ordovician Period

Ordovician Period was the next one after Cambrian.

Ordovician covers the time between 490 and 434 million years ago, just after Cambrian period.

Trilobite Fossil (Niobides Armatus), Ordovician Period, 480 M.Y.A., Bolivia
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During Ordovician, the climate got cooler, probably pretty much as it is today. Australia was still connected to Gondwana continent.

Its eastern third was still under the deep ocean, although inland north Queensland, Gulf Savannah and Cape York peninsula had by now emerged from the water.

Across central Australia, the shallow sea called Larapinta Seaway crossed the continent from west to east and divided it to a southern and a northern part.

Crinoid or Sea Lily Fossil (Scyphocrinites Elegans), Ordovician Period, Morocco
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Sedimentation in the shallow sea produced limestones and sandstones composed from sand eroded from the Precambrian rocks. In the southern part, near Canberra, was a volcanic arc that produced mainly andesites.

When it comes to living things, Ordovician was the birth-time for jawless fish, and the first, primitive land plants like mosses and lichens. In the end of Ordovician there was an ice age and one of major global mass extinctions.

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