The Big Bang of July. The Ordvician(Paleozoic Era)Ordovician Environment

During the Ordovician Period, the surface of the earth was dramatically different than it is today. Nearly all life on earth was in the oceans. The only land life was in the form of very primitive plants very near the water line of the coasts, probably mosses and algae and were of a non-vascular nature. Insects did not yet exist, nor did amphibians or reptiles. Fish as we know them did not exist, although a form of primitive fish began to appear by the end of the Ordovician. Though Ordovician life sounds primitive by today's standards, the life during this period was more advanced than life in the earlier Cambrian Period. Ordovician life was characterized by a dramatic increase of the shelly fauna, corals, and bryozoans. The shelly fauna include the brachiopods which did exist prior to the Ordovician, but were less numerous and mostly inarticulated. The Ordovician introduced numerous articulate brachiopods which have a tooth-and-socket arrangement along their hinge line.


By the end of the Ordovician Period, primitive jawless fish called Ostracoderms appeared. These primitive fish were covered with bony plates and were among the first vertebrates on the earth. The following image shows how the earth looked approximately 450 Million Years ago, during the Late Ordovician Period. The brown areas show the location of the continents. Notice that many of today's continents were covered by shallow seas.