Bridget Ridge, age 13, of Portland, Maine, for her question:

Is it true that camels once lived in America?

The ancestors of the large Old World camels got their start in North America. What's more, their cousins still live way down south of the border. They are natives of the New World    who never left home. True, they have no humps and they are no bigger than large sheep or small ponies. But the large Old World camels and their small South American cousins all share that haughty family facial expression.

In North America, fossils give a clear record of many mammals back through more than 60 million years. About 25 million years ago, the Agate Fossil Beds of Nebraska became overcrowded cemeteries. Among, the buried bones were the skeletons of more than 40 camel ancestors that resembled graceful gazelles. Perhaps they were tapped in an ancient quicksand. Also interred in this ancient cemetery were the fossil remains of rhinos, a pig six feet tall with a skull one yard long and a giant ancestral wolf.

During the Miocene Period, the ancestral mammals shared North America with a whole menagerie of other surprises. Various fossil bearing rocks preserved the skeletons of long gone bears and sloths, early cat and dog types, giraffes and even elephants. Possibly these various mammal families got their start in North America about 50 million years ago.

The dinosaurs had been gone some 10 million years and this was the friendly Eocene Period of geological history. The young Rockies were here, but the Gulf of Mexico reached north to Cairo, Illinois. There it was joined by the lazy young Mississippi River. Across the continent there were stands of green forests and soft, tender grasses carpeted the wide plains. The climate was so warm that figs and magnolias thrived in Alaska. Alligators lurked in the Dakota Streams.

Yes indeed, the Miocene Period was friendly and favorable to the small ancestral mammals. Later, life became harder and the established mammals changed to keep pace with the times. The meat eating types grew stronger and fiercer to cope with competition. The horses and camels grew bigger and taller to outrun their age old enemies. Some of them crossed land bridges into Northern Asia and other emigrated doom into South America.

A million years or so ago, there were no native horses or camels in North America. The globe trotting horses made themselves at home throughout Europe, Asia and Africa. The camel ancestors reached Africa and parts of Asia    where they grew large and adapted to desert life. The other survivors of the Camelidae Family are the llama types of the South American Andes.

The large and lofty Old World camels may loot; like the prosperous lords of the family. But the llamas and alpacas, the guanacos and vicunas are nobody's poor relations. All the evidence indicates that these sturdy little humpless camels closely resemble the family ancestors. Perhaps they should be rated as the true camels that got their start in North America.