what life existed in the ordovician period
The Ordovician Period. The Ordovician Period lasted almost 45 million years, beginning 488.3 million years ago and ending 443.7 million years ago.* During this period, the area north of the tropics was almost entirely ocean, and most of the world's land was collected into the southern supercontinent Gondwana.he Ordovician is best known for its diverse marine invertebrates, including graptolites, trilobites, brachiopods, and the conodonts (early vertebrates). A typical marine community consisted of these animals, plus red and green algae, primitive fish, cephalopods, corals, crinoids, and gastropods.
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.y 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 Silurian Period follows the Ordovician Period in the Paleozoic Era. It began around 443 million years ago and lasted for 26 million years. Like the periods that have come before, it is named for an ancient Celtic tribe that lived in Wales where the geologic evidence was found.Silurian Climate.he Silurian Period follows the Ordovician Period in the Paleozoic Era. It began around 443 million years ago and lasted for 26 million years. Like the periods that have come before, it is named for an ancient Celtic tribe that lived in Wales where the geologic evidence was found. Silurian Climate.