སོལ་ལྕགས་དུས་རབས།
biol. Period of the Paleozoic era, lasting from approximately 345 to 280 mya; formation of widely distributed fern-filled swamps, from which the majority of the earth’s known coal deposits were […]
biol. Period of the Paleozoic era, lasting from approximately 345 to 280 mya; formation of widely distributed fern-filled swamps, from which the majority of the earth’s known coal deposits were […]
