Edward Eichler, Age 7, Of Jamaica. N.Y., for his question:

How did the birds evo1ve?

The ancestors of the feathery birds took to the air while the clumsy dinosaurs walked the earth. At that time, most of the world's population belonged to the reptile clan. In fact, the ancestors of the birds were flying reptiles. They were scaly fellows with claws, toothy jaws and wide leathery wings.

The feathery birds  the sweet songsters and the diving ducks, the swooping eagles and the waddling penguins  have been established for some 60 million years. The stodgy dodo, the jewel toned passenger pigeon and a few other species have perished and become extinct. But in all this time, the rest of the bird world has changed very little.

The earliest birds took to the air perhaps 150 million years ago, and, at that time, it was stylish for birds to have teeth and claws. Science pieces together the family trees of the animals from fossil bones and other remains left buried in the earth's crust. These records must be durable to last through millions of years, and the birds, with their light bones and soft feathers, have fragile bodies.

The fossil records of the birds, then, are very scarce, and there is not a lot of evidence to reconstruct their family trees. But we know that the dainty darlings descended from the bulky dinosaurs. Their ancestors were lizards when they took to the sir in the remote age of reptiles. The oldest bird fossil we have was found embedded in the hard limestone of Bavaria.

This early bird has been named archaeopteryx  the very old winged one. His slender body had a long lizard type tail and a long lizard head with a pair of toothy jaws. Each of his wide wings was fitted with three sharp claws. But his body was covered with feathers, and he could fly. His wings were fringed with stiff pinions, and there was a border of stiff feathers on each side of his long tail.

The few fossil records indicate that a large variety of birds evolved during the next 100 million years. Gradually, their bones and bodies became lighter, and they became better fliers. The claws on the wings went out of style, and there have been no teeth in the bird world for 60 million years. At some time, the birds became warm blooded animals . But all our modern birds still lay eggs as did their remote lizard ancestors.

Archaeopteryx was no long distance flier, but he could make short hops, and the claws on his wings and feet made it easy for him to climb up the trees. He shared the Jurassic period with other early birds. A pigeon sized bird ancestor and another bird two feet long were fatherless and swooped around on leathery wings. They looked like flying lizards, which is what they were. The fossil remains of hesperornis,. the western bird., was found in America. This fellow was a six foot marsh bird. He had already given up flight, and his wings were adapted as diving flippers.