Roberta Sands, age 11, of New Orleans, La,, for her question:

How long ago did birds begin to fly?

The first flying creatures took to the air when the animal kingdom was dominated by the giant dinosaurs. The brontosaurus, weighing up to 40 tons, wallowed for plant food in the warm swamps. Stegosaurus, big as an elephant, used his armor plated spine to protect himself from the claws and six inch teeth of tyrannosaurus rex    the king of tyrants.

Into this world of massive, cold blooded reptiles came the first flyer    himself a massive, cold blooded reptile. This was about 150 million years ago and the creature has waited ail this time for his fossilized bones to be discovered and receive a name. He has been named pterodactyl   tero dak til. .

Pterodactyl was far more hideous than any imaginary dragon, He¬ was featherless and his long, reptile snout was filled with teeth. His wings were extentions of tough skin from his body to his"four outstretched legs. One toe of the front feet extended along the upper edge of the wings. Behind he carried a long featherless tail and his total wingspread was often 11 feet. It is thought that his body carried air sacs to lighten his weight for flying, much as a modern bird carries air sacs.

How successfully pterodactyl used his air sacs and huge wings for flying we do not know. His stay on earth was short, maybe only a few million years. Unknown to him, the true birds had begun to develop. This was still while the mighty dinosaurs were at their peak.

Skeletons of this true bird have been found in Europe. They prove that he was descended from a different type of reptile than the pterodactyl. He has been named the archaeopteryx   arky op ter ix.

Archaeopteryx was warm blooded and he was feathered. His body was no larger than a crow’s, but behind him stretched along slender tail broadened by a row of flat feathers on either side. Archaeopteryx had, three claws on the front edge of each wing and his long beak con¬tained two rows of sharp teeth.

Several other types, of early birds. have been discovered, some in America.  It seems to have been the fashion then for birds to have teeth, even age  3 ate as a~I00 million, years ago. A five foot diving bird with fine teeth was discovered fossilized in chalk beds in Kansas. This bird, however, was no flyer, though a good swimmer and diver. Fossils of a gull like bird have also be found.  .along with their sharp teeth for feeding on fish.

The modern birds began to develop within the last 100 million years. Records of the rocks show that they have not changed very mach in the last 60 million years when many of the present bird types care