425 मिलियन से 405 मिलियन साल पहले; पहले वायु-श्वास जानवर

Noun:

ब्रिटेन की प्राचीन सिल्यूर जाति संबंधी,

silurian's Usage Examples:

Phosphatic beds, supposed to have had a coprolitic origin, are found in the Lower Silurian rocks of Canada.

The lodes occur in Silurian metamorphic micaceous schists, intruded by granite, porphyry and diorite, and traversed by numerous quartz reefs, some of which are gold-bearing.

Silurian rocks are well developed in western Tasmania, and the Silurian sea must have washed the south-western corner of the continent, if the rocks of the Stirling Range be rightly identified as of this age.

In the western Sierras, which are more or less closely attached to the main chain of the Cordillera, Cambrian and Silurian fossils have been found at several places.

Cambrian, Ordovician and Silurian beds have been recognized, the Upper Cambrian consisting of a limestone which is very rich in metalliferous ores (especially galena and calamine).

They became extinct in Palaeozoic times, and are chiefly found in the Upper Silurian, though extending upwards as far as the Carboniferous.

The best Silurian sequence is in New South Wales.

This Silurian sea was less extensive than the Ordovician in Victoria; but it appears to have been wider in New South Wales and in Queensland.

The Silurian system was marked by the retreat of the sea from central Australia; but the sea still covered a band across Victoria, from the coast to the Murray basin, passing to the east of Melbourne.

The oldest rocks of Elba consist of schist and serpentine which in the eastern part of the island are overlaid by beds containing Silurian and Devonian fossils.

silurian's Meaning':

from 425 million to 405 million years ago; first air-breathing animals