NEWARK, N.J. (AP) _ Two young rock collectors who dug up some 400-million-year-old fossils are stars to their third-grade classmates, but geologists say the finds are nothing new to scientists.

Kwasi Brown and Abdul Freeman, both 8, found the fossils of tiny clam-like marine creatures a little more than a month ago while digging in a trash- strewn vacant lot.

Linda Fraser, Abdul's teacher at Alama Flagg Elementary School, was pleased with the boys' find but said Tuesday she never suspected the fossils were 400 million years old.

The fossils' age was discovered after Vice Principal Marc Katz asked a Rugters University paleontologist to examine them.

Joseph Hull, a Rutgers geology professor, said Tuesday he was thrilled for the boys, but that scientists have unearthed many fossils like theirs.

The most interesting aspect of the fossils is that they were found in an urban area, said Hull.

''It's unusual in a highly urbanized area, where everything is concrete and asphalt and buildings, that there are still boulders and you can find things like this,'' he said.

The fossils are of brachiopods, a marine creature that lived attached to rocks or beaching pilins in shallow water 300 million to 400 million years ago. Hull said the animals were carried from New York by a glacier that moved across the continent 10,000 years ago.

Ms. Fraser said her students became excited about digging for rocks after she showed them purple amethyst crystals hidden inside a nondescript black rock. ''That really motivated them,'' she said.

Abdul and Kwasi said they unearthed the fossils in a vacant lot near their baby sitter's house where they often play after school. The boys beamed Tuesday as they displayed their fossils to their classmates.

''We were playing out there when we found them,'' Kwasi said. ''We were excited.''