Ordovician period


  • WordNet 3.6
    • n Ordovician period from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweeds
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In literature:

The levelling continues through the next (Ordovician) period.
"The Story of Evolution" by Joseph McCabe

In science:

Myr bp, in late Ordovician and Silurian period.
Statistical Approach to Gene Evolution