The Silurian is the third and shortest period of the Paleozoic Era, and the third of twelve periods of the Phanerozoic Eon. As with other geologic periods, the rock beds that define the period's …

The Silurian hypothesis is a thought experiment, [1] which assesses modern science's ability to detect evidence of a prior advanced civilization, perhaps several million years ago. The most …

Silurian Period, in geologic time, the third period of the Paleozoic Era. It began 443.8 million years ago and ended 419.2 million years ago, extending from the close of the Ordovician Period to …

志留紀（Silurian，符號S）是地球地质历史上显生宙 古生代的第三个纪，约开始于4.44亿年前，上承奥陶纪；结束于4.19亿年前，下启泥盆纪。 志留纪时期的 笔石 化石甚多，因此又常被称为“ …

志留纪（Silurian Period）（笔石的时代，陆生植物和有颌类出现）是早古生代的最后一个纪，也是古生代第三个纪。约开始于4.4亿年前，结束于4.1亿年前。日本学者音译（日语志留读 …

Learn about Earth's Silurian period from 443 to 416 million years ago.

The Silurian (443.7 to 416.0 million years ago)* was a time when the Earth underwent considerable changes that had important repercussions for the environment and life within it. …

2014年2月20日 · The Silurian Period occurred from 443 million to 416 million years ago. It was a time of great environmental changes on Earth and saw the first evidence of life on land.

2012年8月10日 · The Silurian is the first period with fossils of extensive non-microscopic life on land. Land fauna included spider-like and millipede-like predators, in addition to herbivorous …

Silurian formations widely scattered around the world display a wealth of natural beauty. Niagara Falls and the 11-km (7-mile) Niagara Gorge on the Canadian-U.S. border are products of …