Question - What does the Silurian period mean?

Answered by: Rose Phillips  |  Category: General  |  Last Updated: 16-06-2022  |  Views: 914  |  Total Questions: 14

? r. n, sy-) is a geologic period and system spanning 24. 6 million years from the end of the Ordovician Period, at 443. 8 million years ago (Mya), to the beginning of the Devonian Period, 419. 2 Mya. The Silurian is the shortest period of the Paleozoic Era. 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. The Silurian is a time when many biologically significant events occurred. In the oceans, there was a widespread radiation of crinoids, a continued proliferation and expansion of the brachiopods, and the oldest known fossils of coral reefs. 443. 8 (+/- 1. 5) million years ago - 419. 2 (+/- 3. The Much Wenlock Limestone Formation of Wales and the Welsh Borderland contains a diverse fauna of well over 600 species (mainly crinoids, corals, brachiopods, trilobites, algae and bryozoans) deposited during the early Silurian when this area was covered by a relatively warm, shallow shelf sea.

419. 2 (+/- 3. 2) million years ago

During this time, continental landmasses were low and sea levels were rising. This meant rich shallow sea ecosystems with new ecological niches. Silurian fossils show evidence of extensive reef building and the first signs that life beginning to colonize the new estuary, fresh water and terrestrial ecosystems.

419. 2 (+/- 3. 2) million years ago

The Devonian is known as the Age of Fishes. It is famous for the thousands of species of fish that developed in Devonian seas. We know this because of the fish fossils found in Devonian rocks. Their name means “shell-skins. ” These animals appear in rock from the late Silurian and early Devonian periods.

443. 8 (+/- 1. 5) million years ago

Red-colored sediments, generated when North America collided with Europe, give the Devonian its name, as these distinguishing rocks were first studied in Devon, England. The Devonian, part of the Paleozoic era, is otherwise known as the Age of Fishes, as it spawned a remarkable variety of fish.

The Silurian world consisted of a vast north polar ocean and a south polar supercontinent (Gondwana) with a ring of approximately six continents. By the Silurian period, a large portion of the Rodinian landmass had become fragmented, and those fragments migrated toward the equatorial region.

The Ordovician Period. The Ordovician Period lasted almost 45 million years, beginning 488. 3 million years ago and ending 443. 7 million years ago. 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.

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.

Anoxia in the pycnocline would have expanded significantly during the Early Silurian from that during the colder climate of the Late Ordovician. SILURIAN OCEANIC AND ATMOSPHERIC CIRCULATION AND CHEMISTRY. Lower Upper Atmosphere Oxygen 65%PAL 35%PAL Continents Lithofacies Shales + -

443. 8 (+/- 1. 5) million years ago

The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites and rudists, while dinosaurs continued to dominate on land.

All of the major animal groups of the Ordovician oceans survived, including trilobites, brachiopods, corals, crinoids and graptolites, but each lost important members. Widespread families of trilobites disappeared and graptolites came close to total extinction.

485. 4 (+/- 1. 9) million years ago