The Marine-Life Era on Urantia · The Crustal-Shifting Stage - The Fern-Forest Carboniferous Period - The Age of Frogs
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In general, these were the epochs of development for fresh-water organisms; little change occurred in the previous marine life. But the important characteristic of this period was the sudden appearance of the frogs and their many cousins. The life features of the coal age were ferns and frogs.