also: シルリアき
Silurian period
Geological period spanning approximately 443–419 million years ago. Used in scientific and educational contexts.
The first land plants appeared during the Silurian period.
Variant spelling using the full stem 'Siluria'; less common than シルル紀.
From English 'Silurian', derived from the Silures, an ancient Celtic tribe of Wales. The Japanese form シルル紀 is a direct adaptation.