Ogden Gerald, Age 16, Of Atlanta, Ga.., for his question:
What was the miocene period like?
Our lush plant kingdom was well established in the miocene age, and among thf teeming animals we would recognize many ancestors of our modern animals. Our mountains and rivers, our plains and prairies were beginning to take on their present shapes. The stage, it seems, was set with thriving plant and animal life to welcarne the human family.
The miocene period lasted some 15 million years, which makes it but a short chapter in the earth's long and eventful history. It opened some 26 million years ago when the climate became eooler and drier. Tropical forests gave way to grassy prairies, and the great plains began to form. The earth's crust buckled and bent, mountains were uplifted and volcanos oozed forth vast areas of lava.
In the west, layers of lava and volcanic ash covered an area of 200,000 miles to a depth of 10,000 to 12,000 feet. A crustal block 400 miles long and 100 miles wide was pushed up 13,000 feet to form the Sierra Nevada. The coast ranges began t0 push up their shoulders, and the Colorado River was busy digging the ditch we call grand canyon.
The Appalachians of the east had become worn down with erosion, and the crustal upheavals of the miocene period uplifted them. The Delaware, the Potomac and other eastern rivers were reborn on the sleep slopes. The great smokies were uplifted 2000 to 3000 feet.
Sedimentary layers of sand and clay washed down the new s1opes, pockets of gold formed in the lava beds, tacky beds of tar and asphalt collected in many areas and the oil reservoirs of Texas were formed.
In the cooler climate, deciduous trees began to outnumber the tropical plants. There were birches and poplars, willows and walnuts, oaks and cherries, plums and almonds. Rushes and reeds, iris and waterlilies thronged the waterways, and the miocene period was bright with a vast variety of flowering plants and trees.
Beetles and bees, butterflies and at least 600 other varieties of insects have been found. Among miocene fossils. Frogs and toads, turtles and crocodiles thrived in the lakes and rivers. The giant dinosaurs were declining, and the miocene world was inherited by the furry mammals. The swamps harbored grebes and geese. Ov18 and grouse, pigeons and parrots thronged in the woods. Eagles and falcons, kites and vultures took to the air, and plovers and sandpipers waded on the miocene beaches.
The miocene ancestor of the horse was a three toed trotter no more than 40 inches tall. The miocene elephant, complete with tusks and trunk, was eight feet tall, and there were beavers as big as smau bears. There were ancestors of the dogs and cats, lemurs and monkeys. Perhaps the most amazing miocene animal was a tailless ape, very like the apes of today.