[si-loo
r-ee-uhn, sahy-] 
| 1. | of or pertaining 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. |
| 3. | Geology. the Silurian Period or System of rocks. |
| Si·lu·ri·an (sĭ-lŏŏr'ē-ən, sī-) adj. Of or belonging to the geologic time, system of rocks, or sedimentary deposits of the third period of the Paleozoic Era, characterized by the development of jawed fishes, early invertebrate land animals, and land plants. See Table at geologic time. n. The Silurian Period or its system of deposits. [From Latin Silures, an ancient people of southwest Wales, where the rocks were first identified.] |
Silurian (sĭ-l r'ē-ən) Pronunciation Key
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. See Chart at geologic time. |