Ordovician Period |
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The Ordovician Period lasted from 488 to 443 million years ago. It represents 45 million years of earth history. During to Ordovician, most of the northern hemisphere was covered with water and Gondwana in the southern hemisphere was a the major land mass. |
This is the Martinsburg Formation. A deposit near I81 in Lebanon. PA was so popular that digging threatened the highway and is no longer available.
 Brachiopods and byozoan. There is a large braching bryozoan in lower center of the image. |
 Brachiopods |
 Possibly a sponge |
