Phanerozoic aeon, n.
the period from about 540 million years ago until the present, a period when abundant life existed
<noun.time>
Phanerozoic Phanerozoic aeon Phanerozoic eon
Word
the period from about 540 million years ago until the present, a period when abundant life existed
<noun.time>
Phanerozoic Phanerozoic aeon Phanerozoic eon