Silurian

[ si-loor-ee-uhn, sahy- ]

adjective

1. of or relating to the Silures or their country.
2. Geology. noting or pertaining to a period of the Paleozoic Era, occurring from 425 to 405 million years ago, notable for the advent of air-breathing animals and terrestrial plants.

noun

1. Geology. the Silurian Period or System of rocks.

Silurian

/ saɪˈlʊərɪən /

adjective

1. of, denoting, or formed in the third period of the Palaeozoic era, between the Ordovician and Devonian periods, which lasted for 25 million years, during which fishes first appeared
2. of or relating to the Silures

noun

1. the Silurian
   the Silurian period or rock system

Silurian

/ sĭ-lr′ē-ən /

1. The third period of the Paleozoic Era, from about 438 to 408 million years ago. During this time glaciers that formed during the late Ordovician melted, causing sea levels to rise. The first coral reefs, fish with jaws, and freshwater fish appeared, and jawless fish continued to spread rapidly. The first vascular plants also appeared, as did land invertebrates including relatives of spiders and centipedes.
2. See Chart at geologic time

Other Words From

• post-Si·luri·an adjective
• pre-Si·luri·an adjective noun

Word History and Origins

Origin of Silurian¹

First recorded in 1700–10; Silur(es) + -ian

Example Sentences

Although its evidence points to higher oxygen levels than some models suggest for that time, it’s possible that oxygen was a substantial component of the atmosphere even earlier than the Silurian, he says.

From Science News

Perhaps we are the trilobites of a new Silurian period; well, trilobites were painfully common, but we need not be.

From Project Gutenberg

The prevalence of the brachiopods in the Silurian period over the cephalaspid proves little.

From Project Gutenberg

The Silurian rocks, as regards oceanic life, are perfect and abundant in the forms they have preserved.

From Project Gutenberg

They are, perhaps, the predecessors of the curious Graptolites, which we shall have to represent in the Silurian.

From Project Gutenberg

Undoubtedly the geographical arrangements of the Silurian period contributed to this.

From Project Gutenberg