Learn more about the time period that took place 488 to 443 million years ago. During the Ordovician period, part of the Paleozoic era, a rich variety of marine life flourished in the vast seas and the first primitive plants began to appear on land—before the second largest mass extinction of all time ended the period.

Sponges, corals and even primitive fish lived in Ordovician waters. The plant life in the water was red and green algae.

All the analyses indicate that land plants first appeared about 500 million years ago, during the Cambrian period, when the development of multicellular animal species took off.

Beginning in the Ordovician Period, a series of plate collisions resulted in Laurentia, Siberia, and Baltica becoming assembled into the continents of Laurussia by the Devonian and Laurasia by the Pennsylvanian (also see Cambrian Period). During the Ordovician, many new species replaced their Cambrian predecessors.

For most of the Late Ordovician life continued to flourish, but at and near the end of the period there were mass-extinction events that seriously affected conodonts and planktonic forms like graptolites. The trilobites Agnostida and Ptychopariida completely died out, and the Asaphida were much reduced.

From the Lower to Middle Ordovician, the Earth experienced a milder climate — the weather was warm and the atmosphere contained a lot of moisture. However, when Gondwana finally settled on the South Pole during the Upper Ordovician, massive glaciers formed, causing shallow seas to drain and sea levels to drop.

Ordovician Period, in geologic time, the second period of the Paleozoic Era. It began 485.4 million years ago, following the Cambrian Period, and ended 443.8 million years ago, when the Silurian Period began. Ordovician rocks have the distinction of occurring at the highest elevation on Earth—the top of Mount Everest.

The Ordovician Period started at a major extinction event called the Cambrian–Ordovician extinction events about 485.4 ± 1.9 Mya (million years ago), and lasted for about 44.6 million years. It ended with the Ordovician–Silurian extinction event, about 443.4 ± 1.5 Mya (ICS, 2004) that wiped out 60% of marine genera.

443.8 (+/- 1.5) million years ago

Whilst on our fossil hunting trip we were asked how the Silurian got its name. The Silurian was named by Sir Roderick Murchison, the wealthy Scottish aristocrat. Sir Roderick named the rock strata that made up the chronological succession of fossils the Silurian after an ancient Welsh Celtic tribe called the Silures.

Paleozoic

The Devonian, part of the Paleozoic era, is otherwise known as the Age of Fishes, as it spawned a remarkable variety of fish. The most formidable of them were the armored placoderms, a group that first appeared during the Silurian with powerful jaws lined with bladelike plates that acted as teeth.

Silurian Marinescape Artist’s depiction of Silurian animals, including, from left: bryozoans, crinoids, clams, cephalopod, jelly, sea scorpion (Pterygotus), brachiopod, jawless fish (Birkenia), gastropod shell, brittle star, trilobite, bivalve mollusk, sponges, sea star.

The Silurian Climate The climate was much warmer during the Silurian Period. This caused the glaciers to melt and the seas to rise. Even though the sea level was rising, there were places where the land was slowly rising as well.

450 million years ago Late Ordovician. Life continued to flourish during the Ordovician as it did in the earlier Cambrian period, although the end of the period was marked by the Ordovician-Silurian extinction event. The seas are diverse and the first coral reefs have emerged.