Possible Clues:

• Epoch in which grazing mammals became widespread
• Old age has come in, rocking, beginning to explode
• Of the Tertiary period preceding the Pliocene epoch
• Of the fourth epoch of the Tertiary period
• Poor income, little energy and no people at this time
• Dig around green, reviewing ancient period
• Geological epoch when mastodons appeared
• A geological epoch
• Geological epoch from 23 to 5 million years ago, in which bipedal hominids evolved
• Epoch when the Mediterranean Sea nearly dried up