Fossil remains of the largest seabird ever to soar above the world's waterways, a 90-pound bird with wings measuring 18 feet across, have been discovered and identified by scientists in Charleston, S.C.

The bird, thought to be an ancient relative of the pelican, lived about 30 million years ago, according to paleontologists from the Smithsonian National Museum of Natural History.

The bird was a member of a family called pseudodontorns, or bony-toothed birds, so named for the long teeth that protrude from their upper and lower jaws.

The overall structure of the bird's wings indicates that it had a life style more similar to that of the albatross than the pelican. Because of its unusual wing structure, scientists believe the pseudodontorn used ocean winds to float above the water for miles without flapping its wings.

The fossil was unearthed in a 20 square-foot block of hardened sand and silt that was excavated in 1984 at the Charleston Airport by two scientists with the Charleston Museum. The rock, exposed while ditches were being dug around the airport, was from the Oligocene period.

Fragments of a small pseudodontorn were visible on the surface of the block, but no one at the time knew the importance of the material hidden within. The block remained in storage for almost three years before it was taken to the Smithsonian for examination.

Although many parts of the wing and legs were crushed and fragmented, all important features of the big bird's bones were preserved.

Among extinct flying birds, the big pseudodontorn was surpassed in size only by a fossil of a vulture-like bird from Argentina with a wingspan of 20 to 25 feet.

The pseudodontorn's family lived long and well, according to scientists. It survived for almost 45 million years from the Paleocene period to the Pliocene period. The birds roamed widely across New Zealand, Peru and the sub-Antarctic in the Southern Hemisphere to Europe, Africa, the Soviet Union and North America.

The birds were heavily dependent on strong oceanic winds for their locomotion, and in the United States specimens have been recovered from Maryland to South Carolina and in California and Oregon.